Soft exosuit for assistance with human motion

ABSTRACT

In at least one aspect, there is provided a system for generating force about one or more joints including a soft exosuit having a plurality of anchor elements and at least one connection element disposed between the plurality of anchor elements. The system also includes at least one sensor to determine a force the at least one connection element or at least one of the plurality of anchor elements and to output signals relating to the force, at least one actuator configured to change a tension in the soft exosuit and at least one controller configured to receive the signals output from the at least one sensor and actuate the at least one actuator responsive to the received signals.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a U.S. national stage under 35 U.S.C. §371 ofInternational Patent Application No. PCT/US2013/060225, filed on Sep.17, 2013 which claims priority to, and incorporates by reference in itsentirety, U.S. Provisional Patent Application Ser. No. 61/701,970,titled “Soft Wearable Motion Sensing Suit for Lower Limb BiomechanicsMeasurements,” filed on Sep. 17, 2012, U.S. Provisional PatentApplication Ser. No. 61/829,686, titled “Method and System for AssistedMotion,” filed on May 31, 2013, and U.S. Provisional Patent ApplicationSer. No. 61/873,433, titled “Soft Exosuit for Assistance with HumanMotion,” filed on Sep. 4, 2013.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH

Some aspects of the present disclosure were made with governmentsupport, under Grant No. W911QX-12-C-0084 awarded by the U.S. Army, andthe government shares rights to such aspects of the present disclosure.

Some aspects of this present disclosure were made with governmentsupport, under NSF Grant No. CNS-0932015 awarded by the National ScienceFoundation, and the government shares rights to such aspects of thepresent disclosure.

TECHNICAL FIELD OF THE INVENTION

The present concepts are generally directed to methods and systems forassisted motion in humans and, more particularly, to methods and systemsfor providing assistance with motion and reducing the energy expendingduring motion (e.g., walking) by passively and/or actively addingassistive energy to one or more movements.

BACKGROUND OF THE INVENTION

Prior art systems for assisted motion utilize exoskeletons, comprisingrigid components (e.g., linkages) and joints (e.g., pin joint), attachedto the user's body with the exoskeleton joint(s) being disposed to havean axis of rotation ideally collinear with a natural axis of rotationfor adjacent joint(s). Exemplary prior art exoskeletons are shown in USPublished Patent Application Nos. 2007/0123997 and 2011/0040216, both toHerr et al., and both of which are incorporated by reference herein intheir entirety. Such rigid exoskeletons provide the ability to replacehuman movements that have been lost or severely compromised and areaccordingly designed to enhance the user's stability, balance andsafety. Other rigid exoskeletons serve as a platform to provide physicaltherapy sessions in a clinical environment, such as in a physicaltherapy clinic, or serve to assist able-bodied users to perform tasksmore easily or for longer duration.

However, these rigid exoskeletons rely on rigid frameworks of linkages,coupled to the body at select locations via pads, straps, or otherinterface techniques. As the user flexes or extends their limbs, theserigid links move in parallel with the limb, adding considerable inertiato movement which must be overcome by motors or by the user. Thoughgreat effort has been made to reduce the weight and profile of thesedevices, they still cause considerable restriction to the user's motionand, in particular, add considerable impedance to the natural dynamicsand kinematics of gait. This change to the normal kinematics of walkingis one reason why these exoskeleton systems do not reduce the metabolicpower required for locomotion. The rigid links also cause difficulty,particularly at the extremes of motion, because the pin-joints of theexoskeleton do not precisely match with the axes of the human joints,which move through intricate three dimensional paths. This causesmisalignment of up to 10 cm during normal movement, causing pain andeven injury to users. One solution has been to include redundant,passive degrees of freedom to allow the exoskeleton to travel and deformin key areas for wearer motion, however, this adds further weight to thesystems.

SUMMARY OF THE INVENTION

The present concepts are directed to methods, systems, and devicesconfigured to assist movements of a user, and more particularly tomethods, systems, and devices relating to a soft exosuit comprising aplurality of non-extensible or semi-extensible elements flexibleconnection elements (e.g., webbing, straps, cords, functional textile,wires, cables, composites or combinations thereof, etc.), disposedbetween a plurality of anchor points or anchor areas (e.g., iliaccrests, shoulders, thigh, ankle, calf, etc.), and one or more actuatorsadapted to selectively create tension in selected flexible members attimes at which the transmitted forces to specific limbs or body partswould be beneficial to movement of the specific limbs or body parts. Thesoft exosuit, as described herein, generally refers to and includes awearable device utilizing flexible connection elements to provideassistive forces to at least one limb (e.g., a leg) or portion of a limb(e.g., a foot). In some aspects, the soft exosuit utilizes flexibleconnection elements to provide assistive forces to a plurality of limbs(e.g., two legs) or a plurality of portions of one or more limbs (e.g.,two feet). It at least some aspects, apart from actuating one or morejoints in opposite legs or opposite arms to facilitate motions whereinthe limbs move in different directions at different times (e.g.,walking), the present concepts also include actuating more than one limbat one time and includes, for example, coupling legs to each other,coupling leg and arm movement (same side or opposite side), coupling armmovement, or coupling other body movements to exploit potentiallysynergetic movements.

As compared to the prior art rigid exoskeletons, the soft exosuit islighter, more comfortable to wear and permits a more complete, and morenatural, range of joint(s) motion(s), while still being able to transferforces or torques able to beneficially assist motion. In accord with thepresent concepts, the flexible connection elements can optionally beused in combination with rigid or semi-rigid connection elements and itis not necessary that all connection elements be flexible.

In at least some aspects of the present concepts, a wearable softexosuit includes a first anchor element configured for positioning at ornear a first body part of a person wearing the wearable soft exosuit anda second anchor element configured for positioning at or near a secondbody part of a person wearing the wearable soft exosuit. The softexosuit also includes a plurality of connection elements extendingbetween the first anchor element and the second anchor element, and atleast one of the plurality of connection elements spanning at least onejoint disposed between the first anchor element and the second anchorelement, at least one actuator and at least one controller configured toactuate the at least one actuator at a predetermined time duringmovement of the at least one joint to generate a beneficial moment aboutthe at least one joint.

In at least some other aspects of the present concepts, a system forgenerating force about one or more joints includes a soft exosuitcomprising a plurality of anchor elements and a plurality of connectionelements disposed between the plurality of anchor elements, at least onesensor to determine a force in at least one of the plurality ofconnection elements or at least one of the plurality of anchor elementsand to output signals relating to the force, at least one actuatorconfigured to change a tension in the soft exosuit and at least onecontroller configured to receive the signals output from the at leastone sensor and actuate the at least one actuator responsive to thereceived signals.

In at least some aspects, the soft exosuit connection elements aredisposed in a wearable matrix defining a plurality of nodes, points orregions at which a plurality of connection elements are interconnected,and are connected directly or indirectly to a plurality of anchorpoints. The forces on a node are controlled in part by the configurationof connection elements (e.g., number of connection elementsinterconnected at the node, the relative angles of each of theconnection elements interconnected at the node, etc.) and the appliedforces along each of those constituent connection elements. Duringmotion, soft exosuit actuator(s) selectively apply tensile forces alongthe connection elements to selected node(s) and/or anchor point(s). As aresult of the applied tension, moment forces are created in one or morejoints. When these moments are in the same direction as the naturalmoments created by the musculature, these moments are consideredbeneficial moments and assist with motion (and/or absorb power),requiring less energy from the user and reducing the metabolic cost ofthe motion.

The magnitude and direction of the moment applied by the actuator(s) andassociated connection elements at each joint are determined based on thelocation of the connection elements relative to an axis of rotation ofthe joint. The magnitude of the moment can be determined based on theoffset of the tension forces relative to the axis of rotation of thejoint, such offset being affected by the user's natural body structures(e.g., muscle, fat, etc.), clothing (e.g., boots), and intermediaryelements (e.g., anchor elements connecting the anchor point to aconnecting element). The soft exosuit is configured, in at least someaspects, to advantageously reduce moments that are not beneficial bydisposing connecting elements to symmetrically pass on both sides of ajoint, thereby applying substantially balanced forces to each side ofthe joint. The soft exosuit can still further reduce undesirable momentsby configuring the soft exosuit flexible elements pass as close aspossible to, if not overlying, the joint's axis of rotation. Elements inthe soft exosuit that resist extension can prevent a point (e.g., a nodeor another point) on the soft exosuit from moving in the direction whichwould cause the element to extend. Placing several such elements arounda point (e.g., node) on the soft exosuit can restrain that point (e.g.,node) from moving despite a number of different force vectors actingthereupon, thereby limiting movement of that point with respect to thebody.

In at least some aspects, the soft exosuit comprises a control systemconfigured to monitor one or more parameters (e.g., a resultantstiffness of the soft exosuit, joint angles, heel strikes, etc.), andpreferably a plurality of parameters, to guide the application of forcesfrom one or more actuators to selected flexible connection elements. Theapplied forces can be applied intermittently as appropriate to themovement to be assisted, the level of force required, comfort and/orperformance.

In at least some aspects, the stiffness of the soft exosuit, andtherefore the ability of the soft exosuit to produce resulting tensionchanges, is a variable that is influenced by many different factors suchas, but not limited to, degree of adaptation of the soft exosuit to auser's anatomy (e.g., placement of nodes relative to joints, etc.), thesoft exosuit material(s), the soft exosuit element configurationstiffness (e.g., disposition of nodes and anchor points), and the user'sbody stiffness (e.g., a user's body stiffness is higher if the user'smuscles are tensed, rather than relaxed). By way of example, a stiffnessof the soft exosuit can be selectively enhanced through the use ofnon-extensible or semi-extensible element(s) across a joint. As afurther example, in at least one aspect, such enhancement of stiffnessthrough the use of non-extensible or semi-extensible element(s) across ajoint is preferentially on only one side of the joint rather than bothsides of the joint so that, when the joint is at its point of maximumflexion or extension, as a result, the soft exosuit becomes tenser as aresult of the body's configuration but slack during otherconfigurations, when the joint is not at its position of maximum flexionor extension. In yet other aspects, the soft exosuit is tensioned usinga multi-articular system configured to create tension across multiplejoints due to the combined motion of those joints. Suit pre-tension canbe used to increase the resulting tension force in the overall systemand may be achieved by, for example, tensioning (e.g., passively oractively changing the length of prior to use and/or during use) softexosuit connection elements between nodes and/or anchor points (e.g.,between the hip/ground and the thigh conical section) or by reducing theoverall length of the connection elements between nodes and/or anchorpoints.

In accord with at least some aspects of the present concepts, theactuator(s) can provide a position or force profile which, inconjunction with the soft exosuit and body position at a time ofactuation(s), provides a desired tension, stiffness and moment about aselected joint or joints. The control system is configured to use theactuator(s) to selectively tension the constituent parts of the softexosuit, such as nodes and connection members. In one aspect, thistensioning is used to dynamically and instantly change a tension of thesystem across one or more joints. In one aspect, this tensioning may beapplied (e.g., an auto tension function) to adjust the soft exosuitperformance, comfort and fit by measuring the force and displacement ofthe actuator unit(s) to identify the most effective exosuit stiffness ata particular moment and/or at a particular point in gait (e.g., whilewalking or running) or stance (e.g., standing).

In general, the disclosed soft exosuit is configured to provideassistance to motion of a user. This motion-based assistance is notlimited to walking or running, as are featured predominantly in theembodiments described herein. Rather, the motion-based assistancedisclosed herein broadly relates to any movement-based assistance, whichmay include, for example, assistance with motion of any one or more bodyparts relative to another body part including, for example, movement ofonly one limb (e.g., one arm relative to the torso, one leg relative tothe hip, or one foot relative to the corresponding leg), a plurality oflimbs (e.g., two arms relative to the torso, two legs relative to thehip, one arm relative to the torso and one leg relative to the hip,etc.), the head and/or the torso. By way of example, an upper-bodyembodiment of the soft exosuit can be advantageously utilized by awheel-chair bound individual to assist with locomotion.

In one implementation, the soft exosuit can be used to assist the motionof a person walking with or without a load, with such assistanceproviding a beneficial reduction in the metabolic consumption of energyby the user and reducing the loading on the soft tissue across thejoints (e.g., ligaments, muscles and tendons), thus also reducing therisk of injury and/or exacerbation of existing injuries or preexistingconditions. This can be particularly advantageous to a soldier walkingwith a load. In yet other implementations, the soft exosuit disclosedherein can be used by injured, disabled and elderly people to increasemobility and/or reduce fatigue (e.g., walking, upper body mobility,rotational movements, pivoting movements, etc.).

In at least some aspects of the present concepts, the soft exosuit ispassive and is configured to generate forces about one or more joints(e.g., the hip, etc.) without the use of an actuator. In such a passivesoft exosuit, the soft exosuit includes an upper anchor element and aplurality of lower anchor elements and a plurality of at leastsubstantially inextensible connection elements disposed between theupper anchor element and the plurality of lower anchor elements anddisposed along paths that transmit force, wherein the connectionelements are configured to provide a restorative torque to the hip tobias the thighs toward a neutral position. The suit acts in parallelwith the muscles to reduce the extension torques required by the body.

In addition to motion-based assistance, the soft exosuit may be furtherutilized for motion assessment, rehabilitation or gait assistanceactivities, and movement training such as by providing resistanceinstead of assistance (e.g., to strengthen muscles, to provide negativefeedback for improper movement, etc.) or by providing correctiveassistance where needed to assist with training (e.g. golf-swingtraining, tennis training, etc.).

Yet further, the soft exosuit can be used by healthy people engaged inactivities for which motion-based assistance is desired, inclusive ofpersonal activities (e.g., hiking, climbing, biking, walking, kayaking,canoeing, skiing, etc.) or work activities (e.g., construction work,refuse collection, freight handling, lawn care, first responders, etc.).Moreover, depending on the activity, the weight of and positioning ofthe actuators and/or power supply, and type of power supply, may also bevaried in accord with the changing design envelope.

These and other capabilities of the soft exosuit are more fullydescribed below.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a figure depicting a first example of a soft exosuit in accordwith at least some aspects of the present concepts.

FIGS. 2A-2D are figures depicting exemplary force vectors for a portionof the soft exosuit of FIG. 1.

FIGS. 3A-3C show kinematic test data with respect to the gait cycle forthe soft exosuit of FIG. 1 depicted mean plus or minus one standarddeviation, with actuation at different points of the gait cycle.

FIG. 4 shows, for the soft exosuit of FIG. 1(a), average metabolic powerfor six different actuator turn-on times during the gait cycle.

FIG. 5 shows an example of a soft exosuit control and power system for apneumatic system utilizing McKibben actuators in accord with at leastsome aspects of the present concepts.

FIGS. 6A-6B show an example of the soft exosuit of FIG. 1 showing thesoft exosuit connector matrix without actuators and the soft exosuitconnector matrix with actuators, respectively.

FIG. 7 is a diagram showing a front view of a second example of a softexosuit in accord with at least some aspects of the present concepts.

FIGS. 8A-8F shows plots (left side) showing hip, knee and ankle momentsgenerated as a percent of gait cycle and (right side) showing hip, kneeand ankle range of motion generated with respect to percent of gaitcycle.

FIG. 9A shows graphs of the joint moments for the ankle, knee and hipover a single step or one gait cycle.

FIG. 9B shows a representation of a movement of a strap extendingbetween the thigh and the heel during the gait cycle.

FIG. 9C shows a representation of a change in path length along the bodyof the soft exosuit of FIG. 7 during the gait cycle responsive tochanges in hip angle.

FIG. 9D shows a representation of a path length between two anchorpoints (the hip and the heel in the example shown) as a combination oflengths s1, s2 and s3.

FIG. 9E shows the convention used to represent the moments at the hip,knee, and ankle.

FIGS. 10A-10B are diagrams showing, respectively a representation of aside view of a soft exosuit according to at least some aspects of thepresent concepts, and representations of perspective views of a softexosuit according to at least some aspects of the present concepts.

FIG. 11 shows a side view of a soft exosuit (V5), according to at leastsome aspects of the present concepts, depicting major components of thesoft exosuit.

FIG. 12 shows an example of a flat pattern layout for a soft exosuit(V5) according to at least some aspects of the present concepts.

FIG. 13 shows a waist belt of a soft exosuit (V5) according to at leastsome aspects of the present concepts.

FIGS. 14A-14B show front and back views of a soft exosuit (V5) accordingto at least some aspects of the present concepts, an upper portion ofwhich is shown in FIG. 13.

FIG. 15 shows graphs of the range of motion for pelvis.

FIG. 16 shows a diagram of a soft exosuit (V5) according to theinvention and the forces transmitted over the individual elements.

FIGS. 17A-17B show, respectively, the soft exosuit of FIG. 16 overlaidon a skeleton showing the positioning of the waist belt and Node 1 andan example of a horizontal misalignment of Node 1 resulting inrotational forces on the thigh brace.

FIG. 18 shows the positioning of the thigh brace of a soft exosuit (V5)according to at least some aspects of the present concepts.

FIG. 19 shows the angle of the calf straps of a soft exosuit (V5)according to at least some aspects of the present concepts.

FIGS. 20A-20B show, respectively, a representation of forces along thethigh brace of a soft exosuit and adjustments that may be made to (1)the location and (2) the angle at which connecting elements exit thethigh brace according to at least some aspects of the present concepts.

FIG. 21 shows a view of a T-connection in the lower portion of a softexosuit according to at least some aspects of the present concepts.

FIG. 22 shows a rear view diagram of attachment members (T-connectors)connecting the boots to calf strap of a soft exosuit according to atleast some aspects of the present concepts.

FIGS. 23A-23B show the alignment of the calf straps with the axis of theknee joint in a soft exosuit according to at least some aspects of thepresent concepts.

FIGS. 24A-24B shows the power requirements graph over a gait cycle in asoft exosuit according to at least some aspects of the present concepts.

FIGS. 25A-25C show a representation of forces acting in the calf strapsin the soft exosuit of FIG. 19.

FIGS. 26A-26C show one embodiment of soft exosuit footwear attachmentaccording to at least some aspects of the present concepts.

FIGS. 26D ₁-26D₅ show views of one embodiment of soft exosuit footwearattachment according to at least some aspects of the present concepts.

FIGS. 26E-26G ₂ show aspects of other embodiments of soft exosuitfootwear attachments according to at least some aspects of the presentconcepts.

FIG. 27 shows a detailed view of one embodiment of soft exosuit footwearattachment according to at least some aspects of the present concepts.

FIGS. 28A-28B shows a detailed view of one embodiment of soft exosuitfootwear attachment, according to at least some aspects of the presentconcepts, showing force paths on the boot from the side and bottom,respectively.

FIG. 29 shows an example of one embodiment of an actuation system,showing a drive box and pulley module, for a soft exosuit according toat least some aspects of the present concepts.

FIG. 30 shows a block diagram of an example of one embodiment of anactuation system for a soft exosuit according to at least some aspectsof the present concepts.

FIG. 31 shows a diagram of connections for sensing components for a softexosuit according to at least some aspects of the present concepts.

FIG. 32 shows a diagram of an analog and digital I/O for a soft exosuitaccording to at least some aspects of the present concepts.

FIG. 33 shows a diagram of a motor controller assembly for an actuatingsystem for a soft exosuit according to at least some aspects of thepresent concepts.

FIG. 34 shows a representation of the controlled actuation of the softexosuit during a portion of a gait cycle in a soft exosuit according toat least some aspects of the present concepts.

FIG. 35 shows an approximation of power input to a motor over a gaitcycle in a soft exosuit according to at least some aspects of thepresent concepts.

FIG. 36 shows an example of a plot of cable displacements as a functionof time in a soft exosuit according to at least some aspects of thepresent concepts.

FIG. 37 shows a Bowden cable end fittings for a soft exosuit actuatorattachment according to at least some aspects of the present concepts.

FIG. 38 shows a load cell arrangement is a pulley model and graph oftheoretical input to output force in a soft exosuit according to atleast some aspects of the present concepts.

FIG. 39 shows examples of parallel and series arrangements for cabletensioning in a soft exosuit according to at least some aspects of thepresent concepts and a diagram of deflecting idler pulley for measuringcable tension in a soft exosuit according to at least some aspects ofthe present concepts.

FIG. 40 shows a series load cell location at an ankle of a user'sfootwear in a soft exosuit according to at least some aspects of thepresent concepts.

FIG. 41A-41B show, respectively, examples of soft exosuits according toat least some aspects of the present concepts wherein forces may beselectively applied to both sides of the hip joint (anterior/posterior)or to the ankle.

FIGS. 42A-42G show, respectively, example of components and systems ofone example of an actuator in accord with at least some aspects of thepresent concepts.

FIGS. 43A-43B show, respectively, an example of a timing pulleyconfiguration for a soft exosuit according to at least some aspects ofthe present concepts and an example of an idler configuration forwebbing utilized in a soft exosuit according to at least some aspects ofthe present concepts.

FIGS. 44A-44C show, respectively, front, back and side views of a softexosuit (V3.2) in accord with at least some aspects of the presentconcepts.

FIGS. 45A-45D show, respectively, front, back and side views of a softexosuit (V4) in accord with at least some aspects of the presentconcepts.

FIGS. 46A-46B shows front view and rear view pictures, respectively, ofan example of a soft exosuit worn by a user in accord with at least someaspects of the present concepts.

FIG. 47 presents a comparison of statistics showing evolution of initialembodiments of soft exosuits in accord with at least some aspects of thepresent concepts.

FIGS. 48A-48B show a bar chart depicting a decrease in weight of softexosuits in accord with at least some aspects of the present concepts asthe inventors developed and improved the technology from soft exosuit(V1) to soft exosuit (V3).

FIGS. 49A-49E show kinematic results for the soft exosuit shown in FIGS.46A-46B in accord with at least some aspects of the present concepts.

FIG. 50 shows a force versus time curve for ankle actuation performancefor the soft exosuit shown in FIGS. 46A-46B in accord with at least someaspects of the present concepts.

FIG. 51 shows metabolic results for different subjects utilizing thesoft exosuit shown in FIGS. 46A-46B in accord with at least some aspectsof the present concepts.

FIGS. 52A-52B show, respectively, a biological metabolic power pie chartand a suit metabolic benefit pie chart.

FIG. 53 shows evolution of soft exosuit stiffness between differentversions of soft exosuits (V3-V7) in accord with at least some aspectsof the present concepts.

FIG. 54A-54E ₃ shows aspects of a soft exosuit (V7) in accord with atleast some aspects of the present concepts.

FIGS. 55A-55B show aspects of a soft exosuit in accord with at leastsome aspects of the present concepts.

FIGS. 56A-56B show aspects of a waist belt for a soft exosuit in accordwith at least some aspects of the present concepts.

FIG. 57 shows aspects of another waist belt (V5) for a soft exosuit inaccord with at least some aspects of the present concepts.

FIGS. 58A-58F show aspects of yet another waist belt (V5) for a softexosuit in accord with at least some aspects of the present concepts.

FIGS. 59A-59D show aspects of yet another waist belt (V7.1) for a softexosuit in accord with at least some aspects of the present concepts.

FIG. 60 shows aspects of the waist belt (V7.1) of FIGS. 59A-59D.

FIGS. 61A-61D show additional aspects of the waist belt (V7.1) of FIGS.59A-59D.

FIG. 62 depicts a soft exosuit in accord with at least some aspects ofthe present concepts configured for actuation of multiple joints.

FIGS. 63A-63B show examples of a soft exosuit in accord with at leastsome aspects of the present concepts configured for actuation ofmultiple joints.

FIG. 64A-64B show a multi-pulley for a soft exosuit configured foractuation of multiple joints in accord with at least some aspects of thepresent concepts.

FIG. 65 shows a rear view of a thigh brace for a soft exosuit in accordwith at least some aspects of the present concepts.

FIG. 66 shows Bowden cable termination points for a soft exosuit inaccord with at least some aspects of the present concepts.

FIGS. 67A-67D show aspects of an actuator for a soft exosuit in accordwith at least some aspects of the present concepts.

FIG. 68 shows aspects of a control scheme for a soft exosuit in accordwith at least some aspects of the present concepts.

FIG. 69 shows aspects of a control scheme for a soft exosuit in accordwith at least some aspects of the present concepts.

FIG. 70 shows aspects a control scheme for a soft exosuit in accord withat least some aspects of the present concepts.

FIG. 71A-71H show aspects of an embodiment of a soft exosuit in accordwith at least some aspects of the present concepts.

FIGS. 72A-72B show (a), front and back views of a passive hip systemaiding hip flexion and (b) front and back views of the same system withadded elastic material in the front in accord with at least some aspectsof the present concepts.

FIGS. 73A-73B show (a) front and back views of a passive hip systemsupporting hip extension and (b) front and back views of a garmentsupporting both hip flexion and hip extension in accord with at leastsome aspects of the present concepts.

FIG. 74 shows a fastening system with an elastic element at the front ofthe suit in accord with at least some aspects of the present conceptswherein the bottom diagram is a cross-section of the suit along thedashed line in the top drawing.

FIG. 75 shows hip joint torque during level walking.

FIG. 76 shows profile, motor position and footswitch signal duringground level walking.

FIG. 77 shows a graph depicting the timing of actuation of the softexosuit during a gait cycle and the corresponding suit force in relationto cable position.

FIG. 78 shows another graph depicting the timing of actuation of thesoft exosuit during a gait cycle and the corresponding suit force inrelation to cable position.

FIG. 79 shows an example of a soft exosuit component (here a footwearattachment element) comprising a haptic actuator to provide userfeedback according to at least some aspects of the present concepts.

FIGS. 80A-80B show an example of soft exosuit components according to atleast some aspects of the present concepts.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present invention is directed to a soft exosuit system that can beused in combination with an actuator system to provide active assistancewith natural motions, such as walking, running, stepping up, steppingdown, etcetera.

In contrast with prior art rigid exoskeletons, the soft exosuit inaccord with the present concepts utilizes flexible materials andactuators to specifically address the human factors challengesassociated with exoskeleton devices and does not have a load bearingexoskeleton, but rather relies on the user's biological skeleton toassist with the application of forces and transfer of load.

The soft exosuit greatly reduces the mechanical impedance and kinematicrestrictions compared to traditional exoskeletons with rigid componentsand does not significantly constrain or restrict the user's degrees offreedom. With such a system, it is possible to add controlled impulsesof energy (e.g., during key portions of the gait cycle), rather thandirect control of limb position(s), to provide assistance to locomotionand reduce the metabolic cost of movement (e.g., walking/load carrying)without significantly constraint of movement.

Initial design parameters utilized data for a 50^(th) percentile male,with the specification that the soft exosuit must be capable ofemulating the forces and ranges of motion of normal walking. Totranslate torques and rotational motion into linear values for McKibbenpneumatic actuators 15 (known to contract 25% during actuation) used inthe soft exosuit 10 depicted in FIGS. 1-6B, anthropometric values werefound for each joint to estimate moment arm and total required travel.By estimating a position relative to joint center, moment arms wereestimated and, knowing the ranges of motion, the required force anddisplacement were determined. On these initial parameters, devicespecifications were developed and are shown in Table I, below, whichshows range, moment, and power during normal walking of 50% male, 79 kgmass, 1.75 m height.

TABLE 1 Range of Moment Moment Max Degree of Freedom motion (deg) (Nm)Arm (m) Force (N) Ankle Plantarflexion 25 100 0.06 1867 AnkleDorsiflexion 10 5 0.06 67 Knee Flexion 60 25 0.07 457 Knee Extension −5* 25 0.07 457 Hip Flexion 35 80 0.12 750 Hip Extension 10 50 0.12 367*Maximum knee extension is less than zero (straight leg) during walking

In the embodiment of the soft exosuit 10 described in FIGS. 1-6B, theactuators selected to assist motion were McKibben pneumatic actuators15. As compressed air is pumped into the pneumatic actuators 15, theyexpand radially and shorten in length, thereby providing actuation. Theapplied force can be modified by changing input pressure. Stroke lengthis determined based on the actuator length. A pneumatic actuator 15 withan active length (excluding end hardware such as fittings and steelloops) of 200 mm was prototyped and force versus displacement data wererecorded on an Instron 5544 load frame system for 1 to 5 bar (14.7 to73.5 psi) input pressures. For this prototype, 4 bar (58.8 psi) waschosen as an operating pressure to provide substantial actuating force,yet provide an additional safety measure, providing forces 40% lowerthan the design pressure of 5 bar. As shown in FIG. 5, air flow from thepressure source 16, via a regulator 17, to the pneumatic actuators 15was controlled by inline solenoid valves 18, and air was supplied fromthe compressor to the system with ⅜ inch OD (¼ TD) tubing, anddistributed from the valves to the actuators with individual ¼ inch OD(⅛ TD) tubes to each actuator.

To adequate assist with dynamic motions, such as assisting with gait,inflation and deflation times of each pneumatic actuator 15 must beconsidered, as the actuators do not inflate and deflate instantaneously.Thus, the precise point of application of force during the movement(e.g., at what percentage of the gait cycle) must be understood anddefined to ensure that forces are appropriately applied to the jointduring inflation and to ensure that deflation occurs rapidly enough soas not to restrict joint motion. As one example, in evaluating thedynamic performance of the McKibben pneumatic actuators 15 utilized inthe soft exosuit 10 of FIG. 1, the force versus time was recorded at 4bar during inflation and deflation and it was determined that forceversus time curve was generally sigmoidal wherein, for inflation, 90% ofmax force (235N) was obtained after 0.316 seconds from when pressure wasapplied and wherein, for deflation, force dropped from maximum force to10% of maximum force in 0.098 seconds. Using this pneumatic actuator 15,the force and power requirements listed in Table 1, above, could be metby selecting the appropriate number of actuators for each degree offreedom. For example, four actuators could be configured in parallel ateach ankle joint to assist with ankle plantarflexion.

Air consumption for the test pneumatic actuator 15 at 4.0 bar, gaugepressure, was determined to consume 0.60 gram (0.021 mol) of air peractuation.

In order to develop a soft exosuit (e.g., 10, FIG. 1) of primarily softcomponents, the present inventors set about to develop a method ofapplying loads to the user using tension, augmenting selected muscles atselected time which relying upon the user's skeletal structure togenerate any compressive, bending, or shear loads required in thesystem. Initial human factors design specifications were to provide asoft exosuit that was (1) lightweight, with minimal inertia added thatcould potentially disrupt normal gait dynamics; (2) non-restrictive soas not to disrupt natural joint kinematics in all body planes and (3)comfortable.

In order to apply a torque to a first location (e.g., at a joint), theactuator(s) (e.g., pneumatic actuators 15 in the example of FIGS. 1-6B)must apply a reaction force to one or more other parts of the user'sbody. As seen above in Table 1, the forces applied to joints duringmovement can be quite high (e.g., 1867 N for ankle plantar flexion of25°). Accordingly, although tight straps or skin-adhesives could be usedto maintain the position of wearable devices, tight straps orskin-adhesives are not desirable means by which to maintain the positionof wearable devices used to apply forces required for actuating thelimbs. Instead, it is presently preferred that tight straps orskin-adhesives be used only to support small loads, such as the weightof the components, and not to apply limb-actuation forces. Further,forces parallel to the skin cause slippage, chafing, discomfort, andpresent a high likelihood of deforming and/or slipping, which wouldrender actuation ineffective.

In the context of a soft exosuit 10 (e.g., FIG. 1), it was determinedthat the reaction forces could be advantageously directed to anchorpoints 12 known to readily support load such as, but not limited to, theshoulders, iliac crest of hips, and plantar aspect of the feet. Theseanchor points are characterized by large bony landmarks near the surfaceof the skin and are able to withstand large applied normal or nearlynormal reaction forces (e.g., at the hips, downwardly directed loadsborne on the top of the iliac crest region are preferable to forces inshear borne along the side of the hip). The inventors further observedthat, during joint motion, some paths on the skin surface change inlength substantially relative to one another (high strain paths), whileother paths on the skin surface exhibit little relative motion (lowstrain paths or lines of non-extension).

Turning again to one design goal of applying moments about one or moreof the hip, knee and/or ankle joints, during motion via a soft exosuit,the inventors determined that the reaction forces from a desiredactuation should be redirected to one or more of the anchor points alongthe lines of non-extension via a matrix of connectors from the desiredactuation point, triangulating with other connectors to maintainstability during normal range of motion while redirecting the forces toterminate at one or more of the anchor points (see, e.g., FIG. 1). Thisconfiguration of the soft exosuit robustly constrains the desiredactuation point, minimizes distortion and effect on range of motion, andtransmits reaction forces to portions of the user's body better adaptedto receive such forces. Consistent with these concepts, the soft exosuit(e.g., 10 of FIG. 1) advantageously utilizes connection elements 20forming triangulation paths selected along lines of non-extension forhip flexion and extension, knee flexion, and ankle dorsi flexion andplantar flexion. In the example of FIG. 1, soft exosuit 10 connects thedistal end of the pneumatic actuators 15 to the ankles and the proximalends of the pneumatic actuators are connected to the hips and/orshoulders, via intermediary nodes 30 and connection elements 20, todistribute forces as broadly as possible and to maintain forces at leastsubstantially normal to the skin.

To illustrate the above concepts, FIGS. 2A-2D show an example of theforces involved in actuation of the knee joint. FIG. 2A shows a firstnode N1 and a second node N2 on opposite sides of the left knee joint.Tension applied between these two nodes are able to actuate (or assistactuation of) the knee in extension. In accord with the presentconcepts, nodes N1 and N2 are desired not to move relative to theunderlying limb and are accordingly rigidly constrained or anchored withsufficient stiffness to resist significant forces (e.g., see Table 1,above). Viewing node N1 from the frontal view in FIG. 2B, it can be seenthat an additional connection is required along a contralateral path tothe anchor point at the ankle, for stabilization. In order to maintainequilibrium and avoid anchor dislocation, F1 must remain within theangle between F2-1 and F2-2 connectors. Similar analyses apply to theanchor point at the proximal end of the pneumatic actuator transmittingreaction forces to the waist belt and/or shoulder harness (if provided),distributing forces along the iliac crest of the hip (and/or to theshoulders).

The soft exosuit 10 of FIG. 1 is shown in FIGS. 6A-6B. In construction,nodes 30 comprising triangular threaded links (Quik-Links) were sewninto a matrix of connection elements 20, formed from nylon strappingmaterial, attaching the nodes to one or more anchor points 12 and/orother node(s). Carabiners, squeeze-release buckles, and oval Quick-Linkswere used as necessary between portions of connector straps tofacilitate donning and doffing of the soft exosuit. The quantity andlength of actuators are selected to achieve the desired force and rangesrequired for the associated degree of freedom for a soft exosuit withhip, knee and ankle joint actuation designed for gait assistance. Tothis end, the soft exosuit 10 of FIG. 6B has twelve McKibben pneumaticactuators 15 attached to nodes 30 and anchor points 12 through a networkof non-rigid connection elements 20, comprising webbing, to leveragelines of non-extension.

In the prototype soft exosuit 10 represented in FIGS. 3A-6B, thepneumatic valves 18 and controller 20 were housed in a back-mountedassembly. Signals from the controller 20 were output to relay board 23which, in turn, controlled the solenoid valves 18 operating thepneumatic actuators 18. Inputs to the controller 20 included tuning box21 and foot switches 22. The tuning box 21 was wrist mounted and enabledthe user to perform real-time, on-the-fly adjustment of onset delays andactuation durations. Heel strikes were sensed viafootswitch-instrumented insoles (B&L Engineering), sending a signal toan Arduino Mega 2560 microcontroller (http://arduino.cc/en/). Uponsensing a heel strike, the controller 20 was configured to initiate atiming sequence for actuating three degrees of freedom on that limb.Each degree of freedom had a programmable turn on time (actuator turn ontime after heel strike) and actuation duration. Heel-strike was sensedfor both feet and was used to initiate delays and actuationsindependently. Timing sequences were identical for both legs to maintainsymmetry, but could be adjusted independently if desired to account forany user asymmetry in gait. Although during testing, compressed aircould be supplied via central compressed air (shop air) or a localcompressor for stationary/treadmill testing, the soft exosuit 10 couldalternatively utilize compressed air supplied by a one or moreback-mounted compressed air tank(s) at 306 bar (4500 psi).

The soft exosuit 10 of FIG. 6B has a total mass of 7144 grams whentethered to a compressor and 9121 grams when using a single user-bornecompressed air tank. The soft exosuit 10 itself has a mass of only 3500grams (suit, pants, shoes, actuators, support straps), minimizing distalmass, known to have greater effect on metabolic cost. The mass of thevalve box and batteries was 3280 grams and the control module, includingthe tuning box 21 was 364 grams. The soft exosuit 10 consumed 0.166 mol(4.8 gram) of air per gait cycle and, assuming a stride frequency of 1Hz, would consumes 9.94 mol per minute. Under these assumptions, a 64in³, 4500 psi compressed air tank contains 41.3 mol (415 gram) of air,and would last for 4.15 minutes of constant walking.

A pilot study using the soft exosuit 10 of FIG. 6B examined theperformance of the soft exosuit 10 in assisting gait by using thepneumatic actuators 15 to enhance ankle joint torque during push off.All other actuators in the soft exosuit 10 of FIG. 6B had theiractuation duration adjusted to zero milliseconds so that they generatedno force. Kinematic and metabolic data were collected at the WyssInstitute's Motion Capture Laboratory in order to quantify soft exosuitefficacy and the effect of the exo-gastrocnemius actuator's engagementtiming on joint kinematics and metabolic power was investigated byvarying the actuator turn on time within the gait cycle. Six actuatorturn on times were investigated, ranging from 10% of the gait cycle to60% of the gait cycle, in 10% increments. As controls, joint kinematicsand metabolic power were also investigated with the soft exosuit 10 in acompletely passive unpowered mode and with the subject not wearing thesoft exosuit. Heel strike of the ipsilateral leg was defined as 0% ofthe gait cycle.

A Vicon® motion analysis system with 8 infrared cameras (Oxford Metrics,Oxford, UK) was used to obtain the kinematics of one healthy malesubject aged 42, 65 kg and 1.73 m tall. The participant walked at 1.5m/s along a 10 meter flat ground walk-way. Trials with a walking speedgreater than ±5% of 1.5 m/s were excluded until three acceptable gaittrials were attained. Motion capture data was collected at a samplingrate of 120 Hz. A total of 44 markers were attached to the participantbased on a modified Cleveland Clinic marker set. Lower body markers wereplaced on the following anatomical landmarks: bilateral anteriorsuperior iliac spines, bilateral apex of the iliac crests, dorsal aspectat the L5-sacral interface, lateral and medial femoral condyles, lateraland medial malleoli, calcaneal tuberosities and the superior aspect ofthe first and fifth metatarsophalangeal joints. Triad marker clusterswere placed on the femora and tibae. Upper body markers where placed atthe forehead, left and right temple, seventh cervical vertebra, sternum,tip of the tip of the acromia processes, humeral lateral epicondyles andthe midpoint between the radial and ulna styloid processes.

Opensim 3.0 was used to perform the inverse kinematic analysis. AnOpenSim 23 degrees of freedom head, torso and lower limb model wasscaled to the subject based on 14 anthropomorphic measurements. Afterscaling the generic model, anatomical joint angles were calculated basedon the three dimensional marker trajectories. Means and standarddeviations of the ankle, knee and hip joint angles with respect to thegait cycle were computed. As shown in FIGS. 3A-3B, the sagittal planehip and knee joint angles remained similar between the no soft exosuit10, passive soft exosuit (no actuation), and actuated soft exosuitconditions. For all test conditions, the hip joint had typical sagittalplane behavior with initial flexion at heel strike, extension throughoutthe stance phase and then flexion during the swing phase (FIG. 3A). Thesagittal plane knee angle for both the passive and actuated test casesalso had a typical pattern with the knee initially flexing from heelstrike through the loading response, extending from midstance to heelrise, flexing from heel rise to toe off and finally extending duringswing (FIG. 3B). However, sagittal plane ankle joint kinematics wereaffected by the actuated soft exosuit 10 (FIG. 3C). Providing additionaljoint torque at the ankle joint via the Mckibben pneumatic actuators 15during the stance phase caused the ankle to become more dorsiflexedduring the loading response and more plantarflexed from the end ofterminal stance to the beginning of pre-swing. The conditions which hadthe actuator turned on at 10% and 60% of the gait cycle caused thegreatest change in ankle joint kinematics with up to approximately 15°of deviation from baseline walking without wearing the soft exosuit 10.In contrast, when the exo-gastrocnemius actuator turned on at 30% of thegait cycle the sagittal plane ankle joint kinematics remained similar tobaseline walking without wearing the soft exosuit and was similar to thesagittal plane ankle joint kinematics when wearing the passive suit withno actuation (FIG. 3C).

In accord with the above testing, the subject's metabolic power wasmeasured for the following eight test conditions: 1) standing at rest;2) walking while not wearing the soft exosuit 10; 3) walking with thesoft exosuit unpowered (passive); and 4-8) walking while wearing thesoft exosuit with actuator turn on times of 10% through 60%, adjusted in10% increments. For each test case, the same subject walked on a leveltreadmill at 1.5 m/s for 8 to 10 min. A Cosmed K4b2 cardio pulmonaryexercise testing device (COSMED USA, Concord, Calif.) was used tomeasure the pulmonary gas exchange (VO₂, VCO₂) during the test. Theaverage metabolic power (W) over a 4 min steady state interval wascalculated and the standard deviation of the metabolic power wascalculated according to inter-breath variability.

As shown in FIG. 4, the average metabolic power for the powered softexosuit 10 conditions was minimized when the exo-gastrocnemius actuatorturned on at 30% of the gait cycle. With this actuator timing theaverage metabolic power (± one standard deviation) while walking was386.7±4.4 W, almost identical to the average power when wearing no softexosuit at all (381.8±6.0 W), and substantially less than walking withthe passive unpowered soft exosuit (430.6±8.6 W). There was a 43.9 W or10.2% reduction in average metabolic power when comparing the poweredand optimally tuned soft exosuit to the passive unpowered soft exosuit.The highest average metabolic power (438.8±3.4 W) occurred when thepneumatic actuators were activated at 20% of the gait cycle.

It was determined that, through proper turning of actuator turn ontimes, the soft exosuit 10 synergistically (and comfortably) enhance theuser's kinematics while minimizing the metabolic power. It was furtherdetermined that improperly provided powered joint torque assistanceadversely alters gait kinematics and adversely increases metabolicpower. The soft, compliant exosuit system disclosed herein is ableutilize the user's underlying bone structure as structural support whilefacilitating passive assistance of motion through tension and activeassistance of motion using an actuator system that can provideadditional force generation above that generated using passive motion.

The soft exosuits according to the present concepts, disclosed above anddisclosed herein, provide numerous advantages over traditional, rigidrobotic exoskeletons. The presently disclosed soft exosuits can bereadily constructed from flexible materials such as, but not limited to,fabrics, cords, wires, cables, webs, functional textiles, and straps. Inaccord with at least some embodiments of the invention, the flexiblematerials are used to form connection elements that are substantiallyinelastic in tension (e.g., to provide stiffness under tension), elastic(e.g., to absorb energy and return energy to the user), and/or acombination of inelastic and elastic flexible materials. Connectionelements formed from flexible materials are substantially lighter thanconventional exoskeleton rigid elements and require less energy to carryand to move (e.g., low inertial impact). Moreover, these flexibleconnection elements are sufficiently conformable to accommodate theuser's natural motion and kinematics and to avoid problems associatedwith joint misalignment typically found in rigid exoskeleton basedsystems.

The anchor points 12 or support features include, but are not limitedto, bony and projecting parts of the body that are covered by arelatively thin layer of skin which can provide low displacement andminimal compliance when the soft exosuit is pressed against the skin(e.g., iliac crest of the hip bone, shoulders, etc.). As noted above,the connection elements 20 (e.g., flexible straps or webbing) are usedto transfer forces to selected nodes 30 and/or anchor points 12 (e.g.,via associated anchor elements). Higher levels of soft exosuit stiffnesscan be achieved by aligning the connection elements 20 in direct pathsand/or indirect paths to the anchor points 12 to the point (e.g., node30) where tension can be applied (e.g., by actuator(s)). For example, inaccord with some embodiments of the invention, the connection elementscan be aligned with the force vectors created as a result of the tensioncreated in the soft exosuit. Alternatively, the connection elements 20and/or nodes 30 can be arranged at angles and positions to permit forcevectors created as a result of the tension introduced in the softexosuit 10 to be applied to joints that are not aligned with thetension.

FIG. 7 shows an embodiment of a soft exosuit 100 in accord with at leastsome aspects of the present concepts. As discussed above, the softexosuit 100 is configured to apply a moment to one or more joints (e.g.,a hip joint and ankle joint as shown in FIG. 7) using one or moreconnection elements (e.g., 102-105, 107). These connection elements canbe pre-tensioned across the joint, such that the tension imposes anassistive moment on the joint. In accord with at least some embodiments,the user can selectively increase or decrease a pre-tension in the softexosuit. This feature of user-selective pre-tensioning modification cancomprise one or more independent channels (e.g., whole suit and/orindependent controls for left/right and/or front/back), controlled by amechanical or an electro-mechanical tensioning device configured toadjust a tension along the channel (e.g., by adjusting a functionallength of one or more connection elements). Pre-tensioning may alsooptionally be adjusted by and/or optimized by the soft exosuitcontroller, with or without user-inputs providing feedback to thecontroller as to acceptable pre-tension comfort. In yet other aspects,the user may advantageously adjust tension in one or more connectionelements or anchor elements by adjusting lengths of one or moreconnection elements or anchor elements (e.g., by looping webbing throughbuckle and using a VELCRO® region for attachment).

FIG. 7 shows a soft exosuit 100 comprising a waist belt 110, a node 115,a thigh brace 120 and connection elements 102, 103 connecting the waistbelt and the thigh brace. The waist belt 110 encircles the waist andengages the iliac crest as a support member. One or more additionalsupport elements (e.g., shoulder straps (not shown)) could also beutilized in addition to, or alternatively to, the waist belt 110. Byallowing the waist belt 110 to tightly conform to the body at a narrowportion of the waist, the natural body features help to maintain thewaist belt in position. The thigh brace 120 provides a support point ornode on the thigh to guide and align the connection elements 102, 103over the hip joint and along the thigh and, owing to the tapered shapeof the thigh, the thigh can be used as a support point that resistsupward tension applied to the thigh brace. Tensioning between the waistbelt 110 and thigh brace 120 enables creation of an initial tensionhigher than would be achieved with the waist belt 110 alone.

FIGS. 8A-8F show plots (left side) showing hip (FIG. 8A), knee (FIG. 8C)and ankle (FIG. 8E) moments generated as a percent of gait cycle and(right side) showing hip (FIG. 8B), knee (FIG. 8D) and ankle (FIG. 8F)range of motion generated with respect to percent of gait cycle. Theconnection elements 102, 103 can be tensioned such that, during walking,the tension in connection elements 102, 103 applies a moment thatencourages flexion of the hip joint at the time when the hip isextended. During the portion of the gait cycle just before pushoff(30-50%), the hip absorbs power. The soft exosuit could aid theabsorption of energy during this time by resisting hip extension.Immediately after this, from 50-70% of the gait cycle, the hip providespositive power. The soft exosuit can aid this power generation as wellby applying a complementary moment to the hip. Further, the connectionelements 102, 103 can be connected (e.g., directly or indirectly viathigh brace 120) to calf connection elements 107 that extend down aroundthe knee and meet at the back of the leg below the calf.

As shown in FIG. 10A, for example, in the back of the leg, the calfconnection elements 107 are connected, in at least some embodiments, toa heel attachment or anchor element that directly (e.g., inside footwearof the user, between a sock or liner and inner surfaces of a user'sfootwear) or indirectly (through footwear) engages the foot (e.g., ananchor point that resists upward tension). The connection element 107can also be attached, or alternatively be attached, directly orindirectly (e.g., via an intermediary anchor element) to a point locatedon the outside of footwear (e.g., a boot). Thus, in some aspects of thepresent concepts, the soft exosuit terminates at the user's foot (orfeet) where the inferior (lower) anchor points comprise anchor membersengaging the user's foot (or feet) or the user's footwear.

In each of the above configurations of anchoring the soft exosuit at ornear the foot or feet of a user, the connection elements are secured andtensioned to promote stiffness of the soft exosuit as well as toeffectively apply forces at the heel to generate the moments needed forplantar flexion (or to assist plantar flexion, which may vary on acase-to-case basis).

In an embodiment wherein forces from the connection elements 107 areapplied to a user's foot or footwear, the force may be applied at thecalcaneus (heel) via, for example, fabric which encompasses the heel,via an insole insert secured under or to the user's foot, or via asock-like webbing structure. The forces may be applied to the heelitself (or to a heel portion of footwear), to assist with dorsiflexion,or may be redirected from the heel to the superior surfaces of the foot(or to superior portions of footwear) via connecting elements, fabric,webbing, or the like (e.g., wires, cables, gears, gear trains, levers,etc. appropriate to the application) to apply a downward force thereonto assist with plantar flexion.

An insole insert may, for example, comprise a rigid or semi-rigidelement enabling forces to be applied at the back of the rigid orsemi-rigid element via a heel connection element. Tension fromconnection elements 102-105 can then be applied to the calf connectionelements 107 to a heel connection element attached to the insole insert(or alternatively to a heel or rear portion of footwear or to heel orrear portion of a sock-like structure or webbing structure disposed overthe foot). The heel connection element can extend under the heel alongthe bottom of the foot and couple to one or more connection element(s)that encircle the superior surfaces of the foot, such that a tensionapplied to the heel connection element causes plantar flexion of anklejoint (e.g., a foot pushing off motion).

In accord with some embodiments of the invention, the soft exosuit isconstructed, designed and optimized for a specific biomechanicalactivity (e.g., walking, etc.). When the body executes a normal,unassisted motion such as walking, the musculature expends metabolicenergy to move the bones of the body and transfer the weight from onefoot to another and provide energy for forward propulsion and resistinggravity. The muscles apply moments to a specific set of joints causingthem to extend and flex in a timed and coordinated manner to take eachstep, such as is represented in FIG. 9A by the joint moments (Nm/kg)expressed as a function of gait percentage for the ankle, knee and hipjoints. In accord with some embodiments of the invention, the softexosuit can be configured to apply a moment or torque at a joint toassist or inhibit the bodily movement with respect to that joint.Whether the moment is beneficial, and assists the motion, or is harmful,and opposes, the motion can be a function of timing of applied motionand the configuration of the connection elements of the exosuit. Motionusually involves reciprocating movement of the body parts around thejoint and the application of an external moment, in a specificdirection, at the proper time can supplement the forces exerted by themuscles to assist the motion. The same moment applied at a time when thejoint is articulating in the opposite direction can oppose the forcesexerted by the muscles and present resistance to the motion.

The connection members of the soft exosuit are naturally offset from thecenter of rotation of the joints by natural body structures (e.g.,larger diameter legs displace the soft exosuit farther from center ofrotation). In at least some aspects of the present concepts, thisdistance could be increased through the use of passive elements, such asspacers (e.g., fabric, foam elements, pads, etc.), or active elements,such as actuators, to increase a distance between the soft exosuit andthe body of the wearer or to dynamically increase a distance between thesoft exosuit and the body of the wearer in the case of such activeelements. Further, as the joints move with respect to one other, theline of action of one or more soft exosuit connection members can changewith respect to the joint, thus changing the moment were a force to beapplied along that connection member. Yet further, the nodes and/oranchor elements may be caused to move during operation of the softexosuit, responsive to applied forces, which can also change the line ofaction of one or more soft exosuit connection members. An example of thechanging line of action of a soft exosuit connection member duringmovement of the joint is represented in FIG. 9B, which shows theconnection member 107 (see also FIGS. 7-8) extending between the thighbrace 120 and a footwear connection element 130 can change positionrelative to the knee axis of rotation “A” as the leg moves through30-70% of the gait cycle. The relative change in position of theconnection member 107 changes the moment that the soft exosuit can applyto or across the knee joint during those phases of movement. Thus, weretension to be applied to the connection member 107 between 30-70% of thegait cycle, the connection member 107 provides a small moment extendingthe knee at 30-40% of the gait cycle, provides almost no moment at theknee at 50% of the gait cycle, and provides a larger moment at 60-70% ofthe gait cycle.

In at least some aspects of the present concepts, the calf connectionelements 107 are disposed to be slightly asymmetrically disposedrelative to one another, with the lateral (outer) calf connectionelement 107 (see e.g., FIG. 9B) being disposed slightly behind the kneeaxis of rotation A and the medial calf connection element 107 beingplaced slightly forward of the lateral (outer) calf connection elementor slightly forward of the knee axis of rotation. This configurationfacilitates directing of tensile forces exactly through the knee centerof rotation at all times. Dynamically, in the early stages of the gait,the medial calf connection element 107 is slightly in front of the kneecenter of rotation, and the later calf connection element 107 is throughit or slightly behind it and, in the later stages of the gait, thisreduces the effective moment arm (and moment) around the knee.

FIG. 9C shows a person moving through different parts of the walkingcycle. A graph of the hip angle over the walking cycle is also shown. Ascan be seen in this example, the hip angle is largest at 0% and 100% ofthe walking cycle, and is smallest at 50% in the walking cycle. Due tothe angle change of the hip and the structure of the body, the pathlength S between the waist belt 110 and the top of the thigh brace 120changes as the body moves through the walking cycle. Accordingly, thesoft exosuit will be tensioned to different degrees during movement. Ifa connection element is provided corresponding to path length S, suchconnection element will draw taut at some points of movement (e.g., 50%of gait cycle) and will grow slack at another point of movement (e.g.,0% of gait cycle). The degree of this natural (non-actuated) state ofthe connection element is influenced, of course, by pre-tensioning andmaterial selection, for example.

FIG. 9D likewise shows an example of a soft exosuit extending acrossmultiple joints and being anchored at the hip via a waist belt 100 (orequivalent waist-positioned connection members) and at the heel via afootwear connection element 130. As defined herein, the footwearconnection element 130 includes any connection elements attached to anoutside of worn footwear (e.g., FIGS. 21-22, 26A-26C), attached to auser's foot (e.g., FIGS. 26D ₁-26D₅, and/or disposed within wornfootwear (e.g., FIGS. 26E-26F). The soft exosuit 100 structure, in thisexample, comprises a first connector element 104 having a length (pathS1) between the waist belt 110 and the thigh brace 110, which itself isshown to have a length S2. A second connector element 107 having alength (path S3) is attached to the bottom of the thigh brace 110, runsalong the lateral gastrocnemius, and is connected to the footwearconnection element 130. The first connector element 104 (S1) will changein accord with changes in the hip angle during movement. The length ofthe thigh brace 110 (S2) is generally fixed, as it extends over asegment of the body that does not traverse any joint. The length of thesecond connector element 107 (S3) will change based on relative changesbetween the knee and ankle angles. As a whole, the distance between thetwo anchor points (the hip and the heel) is a combination of lengths Sl,S2, and S3 and the selective tensioning of the soft exosuit desirablytakes into account the combined effects of multiple joints.

In accord with the invention, by understanding timing of the momentsapplied to that set joints, a soft exosuit can be configured to applymoments to some or all of the set of joints in timed and coordinatedmanner to supplement the moments created by natural muscle movements andenable the body to move at the same rate while expending less metabolicenergy or restoring mobility for those with reduced muscle function.These moments can be created in a passive or an active manner. In apassive configuration, the natural motion can create tensions in thesoft exosuit between the support features and the connected elements ofthe soft exosuit to create moments at specific joints at specific timesduring the motion cycle. In an active configuration, one or moreactuator(s), however powered, can be employed to create tensions in thesoft exosuit that generate moments at specific joints at specific timesduring the motion cycle. In accord with some embodiments of theinvention, the soft exosuit can be configured to actively as well aspassively generate forces on the body that supplement the forcesgenerated by the musculature, to enable the body can to do less work andreduce the metabolic cost of a given motion as compared to theunassisted execution of that motion. This can be accomplished using asoft exosuit configuration that can passively create tensions using thenatural body movement in combination with one or more actuators thatactively applies tension to the soft exosuit in a coordinated manner.

In at least some aspects of the present concepts, the soft exosuit isconfigured to absorb energy from the user's motions, similar to themanner in which the user's muscles absorb energy from the user'smotions. At various times in the walking cycle, for example, the musclesabsorb power, such as to arrest the motion of the torso as it fallsforward under the influence of gravity, or to slow down the leg inpreparation for stance. To absorb power during these and other times,the muscles may contract eccentrically, extending under the appliedexternal force while applying force. To reduce the amount of force themuscles must apply in these situations (or in a situation where power isabsorbed by muscles/tendons when the muscles are isometricallycontracting) and/or to reduce the probability of soft tissue damage, thesoft exosuit can apply force parallel to active muscles at any time toabsorbing power from the body that might otherwise prove potentiallydetrimental or minimally beneficial. This absorbed power could then beharvested via an energy storage device (e.g., a spring system, aresilient member, etc.), and returned to the body at some point later intime (e.g., at a subsequent point in the gait cycle). By way of example,the absorbed power could be harvested by compressing a spring, whichthen will then expand responsive to decreases in the applied compressiveforce. A compressed spring could optionally be temporarily held orlocked using a latch or some other mechanism to retain the spring in thecompressed state until a time which the energy is to be returned intothe soft exosuit system. In another example, the absorbed power could beharvested by converting it to electrical energy and storing the energyin a battery. Potentially, energy could be stored through other meanssuch as, but not limited to, hydraulic, pneumatic, or chemical energystorage appropriate to a given design envelope. Energy storage frompower absorption could occur in both passive and active modes of thesuit. In passive modes, energy storage could use passive mechanisms(e.g., a clutched spring, etc.), while in active mode the soft exosuitcould either use these schemes or additionally use schemes whichdirectly pull on an actuator to generate stored energy, for exampleback-driving the same electrical motor used to actuate the soft exosuitat other times.

As shown in FIG. 10A and FIG. 25A, for example, the calf connectionelements 107 apply a tension on a footwear connection element 130 thatengages the foot. Depending on the position of the calf connectionelements 107 with respect to the knee joint, tension in the calfconnection elements 107 can apply a moment on the knee joint. Bypositioning the calf connection elements 107 forward of the axis of theknee joint, the tension in the calf connection elements 107 canencourage extension of the knee joint and by positioning the calfconnection elements 107 behind the axis of the knee joint, the tensionin the calf connection elements 107 can encourage flexion of the kneejoint. Aligning the calf connection elements 107 through the axis of theknee joint can be used to transfer the tension without creating a moment(beneficial or harmful) on the knee joint.

In accord with a passive configuration embodiment of the invention, thecalf connection elements 107 can be connected by an inelastic member(e.g., cable, strap, etc.) or elastic member to the heel connectionelement, such that during normal walking, the tensions created in thesoft exosuit cause beneficial moments to applied on one or more of theleg joints (e.g., the hip, the knee and/or the ankle) of at theappropriate time to supplement the natural muscle movements. Forexample, a normal walking gait results in a backwardly extending leg atabout half way (50%) through the gait cycle. As a result, a tension iscreated in the soft exosuit that extends from waist belt 110 down theconnection elements 102-105 on the front of the thigh, along the calfconnection elements 107, around the knee and down the back of the leg tothe heel strap. The tension can create a beneficial moment in the hipjoint causing assisting with hip extension and then subsequentlyassisting it to flex and propel the leg forward when the energy storeddue to this tension is released potentially in addition to an activeforce from one or more actuators. The tension can also create abeneficial moment in the ankle joint where it assists with dorsiflexionand subsequently assists with plantar flexion of the ankle in additionto an active force applied by one or more actuators, causing the foot topush off in a forward direction.

In accord with an active configuration embodiment of the invention, auser's motion can be further assisted by adding one or more activecomponents that actively pull on the heel connection element at theappropriate time to increase the push-off energy of the foot. In thisembodiment, the heel connection element can be connected to an actuatedcable or other actuation member that pulls on the heel connectionelement at a predetermined time to apply a beneficial moment about theheel. The actuated cable or other actuation member is connected,directly or through an intermediary power train, to a motor or otheractuator controlled by a controller to apply the force to cause aspecified moment at a predefined time. In one example, a cable (e.g., aBowden cable comprising a substantially incompressible sheath) isprovided to connect the calf connection elements 107 to one or morefootwear connection elements 130 at the back of the leg. Such a forceapplied to assist with push off at the ankle can also assist withflexion at the hip.

In accord with some embodiments of the invention, the soft exosuit isconfigured to provide a plurality of anchor elements disposed at anchorpoints to permit engagement of the soft exosuit with natural features ofthe body that well serve as anchor points. However, in accord with otheraspects of the present concepts, it may be desirable to establish anchorpoints or support point at a location where there is no such naturalfeature of the body, where application of a load would normally haveundesirable consequences. In accord with these embodiments, one or moreconnection elements or struts can be used to transfer the forces fromthe support point disposed at a desired location to a different locationon the body, such as one or more anchor points corresponding to naturalfeatures on the body (e.g., shoulders, iliac crest, etc.).

For example, in the Bowden cable embodiment noted above and shown inFIG. 10A, the Bowden cable sheath can extend from a point on a backpackof the user down along the side of the leg to a location behind thecalf. Thus, the Bowden cable can be fastened to the calf connectionelements 107 at the point where they meet below the calf in the back ofthe leg and the proximal end of the cable sheath is coupled to thehousing of the actuator (e.g., a shoulder-borne backpack comprising adrive motor and pulley system) to help maintain tension in the exosuit.Similarly, as noted elsewhere herein, other cable types or actuationelements (e.g., ribbons, fabric, etc.) can be used and routed (e.g.,though fabric of or channels in the soft exosuit) from the actuator(s)to specific locations at which a force is desired to be applied.

Forces then can be created between the point where the Bowden cablesheath 144 attaches to the soft exosuit and where the central cable 142attaches to the soft exosuit 100. As a result, a tension can be createdin the soft exosuit 100 between the waist belt 110 and the support pointat the end of the Bowden cable sheath 144 that joins to the ankleconnector element 113 at the back of the leg. This tension can bedynamic in the sense that, as the user walks the backpack moves, as doesthe lower leg, changing the distance between the proximal end of theBowden cable sheath 144 and the distal end of the Bowden cable sheaththat provides the connection point 113 for the lower connection membersof the soft exosuit. In addition, the hip also moves, changing thedistance between the anchor point on the hip and the anchor point at thelower leg which can affect the tension in the soft exosuit during use.

Thus, the beneficial moments of the soft exosuit can be enhanced bypassive and/or active components that apply forces that can createbeneficial moments to supplement muscle action. By analyzing thebiomechanics of the natural motion to be assisted and the power expendedby each joint in the execution of motion, supplemental moments can beidentified to receive a desired level of assistance.

For example, during normal walking, power is expended by the body as ittransitions support from one leg to the other in course of propellingthe body forward. A significant portion of this power is provided by thehip and the ankle. FIG. 9A shows a graph of the joint moments for theankle, knee and hip over a single step or one gait cycle. The graphshows that the ankle has a large positive moment at about 50% or mid-waythrough the gait cycle (see also FIG. 46). According to some embodimentsof the invention, walking assistance can be provided by applying apositive moment to the ankle from approximately 35% to 60% of the gaitcycle.

In accord with some embodiments of the invention, the soft exosuit 100can be designed to take advantage of the natural motion of the variousparts of the body, by identifying support points that are or becomefurther apart at a time when a positive moment applied to one or morejoints (e.g., the ankle) can be beneficial. The soft exosuit 100 can beconfigured with connection elements that extend around the joint toestablish a tension using one or more nodes or anchor points to create abeneficial moment about the axis of the joint. In the example of FIG.10A, for example, the soft exosuit 100 can be tensioned between the hip(via waist belt 110) and footwear connection element 130 to create abeneficial plantar flexion moment at the ankle at an appropriate timeduring the gait cycle. In addition, tension in the soft exosuit can beguided over the hip joint, applying a beneficial moment that encourageship flexion and/or over the knee joint, applying a beneficial momentthat encourage knee extension, each or both at point(s) in the gaitcycle when the moments would be beneficial to the hip and/or kneemotion.

Additional metabolic energy can be saved by providing one or moreactuators that can create increased or additional tensions in the softexosuit 100 to provide increased and/or additional beneficial moments.For example, in the soft exosuit 100 shown in FIG. 10A, an actuatorcable 142 can be used to apply a positive moment on the ankle joint bypulling on the heel which is several centimeters displaced from the axisof the ankle joint. As noted above, in one embodiment of the presentconcepts, the cable is a Bowden cable comprising a substantiallyincompressible sheath. In another embodiment, the sheath itself isconfigured to provide dynamic properties, such as by having a resilientsheath that stores and releases energy, or by incorporating a springelement into the sheath.

As noted above, a distal end of the actuator cable 142 is attached,directly or indirectly (e.g., via a connection element) to an anchorelement which, as shown in the example of FIG. 10A, extends from theheel under the foot and then wraps around the top of the foot. A drivemotor and pulley system can be coupled to the proximal end of theactuator cable 142 and the drive motor controlled by an on-boardcontroller (e.g., computer) to actuate the actuator cable during thedesired time period (e.g., 35% to 60% of the gait cycle) to providemotion assistance. Sensors (e.g., foot strike sensors, joint anglesensors, etc.) are advantageously used to synchronize the actuator cable142 cable actuation with the gait cycle of the user. As one example,tensile forces are sensed by force sensors in one or more connectorelements, nodes or anchor elements and these forces are monitored andevaluated by the controller (e.g., could for several cycles of movement)to estimate the gait cycle, following which the controller progressivelyengages the actuator(s) over a few or more cycles of movement or afterinstruction by the user to enable actuation). Alternatively, thecontroller may infer the gait of the user by other feedback, such asmanual inputs from the user or from tensile forces sensed by forcesensors in the straps (e.g., the controller could monitor forces in thestraps for several cycles of movement, following which actuation canprogressively ramp up over a few more cycles of movement or afterinstruction by the user to enable actuation.

As previously noted, the soft exosuit concepts herein are deployable toreduce the metabolic cost of various activities, such as walking, byproviding assistance at specific points of the activity and to reducethe loading on the soft tissue (muscles, tendons and ligaments) acrossthe joint. Where a user expends less energy in the activity (e.g.,walking), the user will be less fatigued than the user would be withoutassistance. Fatigue ultimately leads to a deterioration of performance(e.g., a breakdown of the gait), which can increase the risk of injury.Reduction in metabolic costs can decrease the risk of fatigue-relatedinjury. In accord with at least some aspects of the present concepts,the soft exosuit system is able to decrease the user's metabolism belowthe level experienced by the user when conducting the activity (e.g.,walking) without the soft exosuit. The soft exosuit can also reduce thestresses on the soft tissue by having some portion of the forces at eachjoint born by the soft exosuit.

The soft exosuit 100, shown in FIG. 10A, includes a plurality ofconnection elements comprising, by way of example, a cloth, textile, orwebbing (e.g., synthetic and/or natural fibers, Kevlar, etc.), wornunderneath or on top of the clothing. An actuator unit 200 can be wornon the back (e.g., in a shoulder-borne backpack, attached to ashoulder-borne frame, etc.), on the waist (e.g., attached to a waistbelt, etc.), or in or on a device used by the user (e.g., a bike, awheelchair, a kayak or canoe, a walker, etc.). In FIG. 10A, a Bowdencable unit 140 extends from the actuator unit 200 and connects the softexosuit 100 to the footwear connection element 130. In a configurationwhere the actuator unit 200 is borne in or borne by a device used by theuser, the Bowden cable sheath 144 may be advantageously attached to afixed anchor point (e.g., on waist belt 110) and then the sheath and theBowden cable 142 passed down for attachment to the footwear connectionelement 130. As noted, the soft exosuit 100 comprises one or moreconnecting elements (e.g., 102-105, 107), nodes (e.g., 113) and anchorpoints to control the transmission of forces along, to and from theuser's body. The soft exosuit system 100 also optionally includes a footsensor 150 or actuatable switch to sense the forces applied to the footduring walking or otherwise to actuate (switch on or off) at a point ofsubstantially maximum force corresponding to a heel strike. Sensors ableto be used to assist in the determination of gait, for example, include,but are not limited to foot switches, Inertial Measurement Units (IMUs),accelerometers, Electromyogram (EMG) sensors, strain sensors to detectstrain in user's skin in selected locations, sensors built into the softexosuit to detect tensile and/or shear forces in the suit, sensors in amotor or other actuator to detect the actuator position, sensors inseries with a Bowden cable or part of the Bowden cable sheath to detectthe force in the cable, or other sensors.

In accord with some embodiments of the invention, the soft exosuit 100can include one or more actuator units 200 (see, e.g., FIGS. 10A-10B)that causes the distal end of the cable 142 of the Bowden cable unit 140to retract into the sheath 144. The distal end of the cable 142 can beconnected to the footwear connection element 130, and the distal end ofthe Bowden cable sheath 144 can be connected to the soft exosuit 100 atthe back of the calf. When the cable 142 is retracted, the cable 142pulls upwardly on the footwear connection element 130 and the sheath 144pushes the soft exosuit 100 downward from the attachment point at theback of the calf. The soft exosuit 100 then transfers the forces throughthe connection elements (see, e.g., FIG. 7) up to the pelvis of the uservia the waist belt 110. The user's bone structure then transfers theforce back down to the ankle joint and to the ground through the foot.

The forces generated by the soft exosuit 100 are advantageouslyconfigured to complement the user's musculature by acting parallel tothe user's musculature. This is accomplished by configuring theconnecting elements (e.g., 102-105 in FIGS. 7-8) and nodes (e.g., node1, FIG. 7) to extend along predefined locations along the body. Soconfigured, the user's muscles can be activated less during certainportions of the gait cycle, because the soft exosuit provides theremaining forces necessary for locomotion. This reduction in muscleactivation can be used to lower the user's metabolic rate and reduce thelevel of fatigue experienced over time.

In accord with some embodiments of the invention, metabolic reduction isachieved by applying power to the body at the same times that themuscles generate power and by absorbing power from the body during thetimes that the muscles absorb power. The ankle generates a large pulseof power between about 40-60% in the gait cycle, which extends from oneheel-strike to the next. This power input at the ankle, occurring whenthe leg is pushing the body off the ground, is the largest power burstof any joint throughout the walking cycle. In accord with someembodiments of the invention, assistive forces or moments can be appliedto the joint that experiences the largest power spikes at the pointduring the motion cycle that the musculature generates those powerspikes to achieve metabolic reduction in an effective manner. Forexample, based on the evaluation of joint power, in accord with theinvention, the soft exosuit 100 can be configured to apply assistiveforces to the ankle joint during this point in time, between about40-60% of the gait cycle.

In accord with some embodiments of the present concepts, the softexosuit 100 can extend from the ankle up to the pelvis and canadditionally, or alternatively, create moments at the knee and hip aswell as the ankle. In a multi joint system, the forces applied canaffect each of the joints beneficially, and thereby provide moreeffective assistance. In accord with these aspects, the soft exosuit 100is able to create moments at the knee and/or at the hip at times duringthe gait cycle when such moments would beneficially affect these joints.Natural movements and/or actuators that generate tension or displacementof the soft exosuit at one location/joint can, accordingly, benefit morethan one location/joint.

In accord with some embodiments of the invention, the soft exosuit 100can provide a number of functions. The soft exosuit (e.g., 100) cancreate precisely-controlled beneficial moments through, for example, thehip and/or ankle joints. As previously noted, a moment is consideredbeneficial if it assists the natural musculature. The disclosed softexosuit's architecture and the topology of the connection elementsdesirably are configured to mimic, as best possible, the force vectorsapproximating the forces provided by the user's muscles.

In accord with at some embodiments of the present concepts, the softexosuit is optimized to maximize stiffness (e.g., strapping it securelyto anchor elements at anchor parts of the body). For a low series springstiffness in an ankle exoskeleton, required power increases as 1/k. Itis accordingly desirable to make the soft exosuit as stiff as possibleto provide for higher power efficiency when applying assistive forces tothe wearer. Furthermore, high exosuit stiffness will reduce thedisplacement of the soft exosuit relative to the user's body duringmovement and/or during actuation, thus reducing the risk misalignment ofnodes and connection elements and reducing chafing. It is contemplated,however, that various applications could favor a minimized stiffnessand/or a variable stiffness (e.g., automatically varied by a controlleror manually controlled) that enables the stiffness to vary based on theuser's activity (e.g., to minimize stiffness and enhance transparencywhen assistance is not required and to maximize stiffness and whenassistance is required).

Both the fit of the soft exosuit 100 and its stiffness can be influencedby the exosuit's tension and alignment. If the soft exosuit isimproperly aligned, whether by initial set up or by movement of the softexosuit 100 during use, the moments created will not be optimal and,more significantly, the moments may prove distracting or evendeleterious over time, as they cease to occur where necessary. It isdesirable that the soft exosuit 100 remain in the correct location onthe body even as the user moves and as the soft exosuit is actuated,lest the soft exosuit functionality or efficiency be adversely affected.To facilitate retention of the soft exosuit 100 in the proper placementduring use, it is advantageous to pre-tension the soft exosuit (e.g.,actuator cable(s), connection elements, etc.) following donning of thesoft exosuit. The initial tension in the soft exosuit can be adjustedmanually (e.g., by adjusting strap, buckles, fittings, cables, controlsthat adjust a tension in a plurality of components at the same time,etc.) or automatically using one or more actuators (e.g. a motor-drivenmechanism).

In the example of FIGS. 7-8 and 10, during donning of the soft exosuit100 by the user, the user can tighten the connection elements to makethe soft exosuit comfortably snug. The cable 142, attached to connector113 (which in turn is attached to anchor member 130), is then retractedinto the sheath 144, which pulls the soft exosuit 100 down and theanchor member 130 up, taking any slack out of the cable 142 and creatinga small amount of tension in the system. In accord with some embodimentsof the present concepts, the user can set the tension so to barelydetect the exosuit's presence during movement (e.g., walking). Actuationcan then be applied to the soft exosuit 100 from that point of systemtension.

In accord with some embodiments of the present concepts, actuatoractuation member(s), such as Bowden cables, are used to position themass of the actuation system 200 (FIG. 10A) away from the foot and theankle joint being actuated. Using such actuation member(s), theactuation system 200 can be attached to a user's waist or carried in abackpack. In accord with at least some aspects, an actuation system 200utilizing Bowden cables permits routing of the cable sheath along a paththat does not adversely impact the user's motion. There are many waysthat the sheath 144 of the Bowden cable can be attached to the softexosuit. By way of example, one attachment scheme for the sheathincludes a male/female connector disposed on one or more points of thesoft exosuit, with corresponding male/female connector(s) disposed alongappropriate sections of the cable sheath. In another configuration, thecable sheath 144 can be fixedly attached to the soft exosuit (e.g.,sewing, bonding agents, adhesives, etc.), routed through a formedchannel in the soft exosuit, attached to the soft exosuit using VELCRO®attachment members, or attached to the soft exosuit using with one ormore tying members.

Where the actuation system 200 utilizes Bowden cables, for example, asmall, geared motor is provided to drive a pulley or, alternatively, alarger motor directly driving a pulley can be used to pull on the cable142 to apply an assistive force on the heel, as shown in the example ofFIG. 10A. Other drive mechanisms can be used, of course, such as, butnot limited to, linear motors and hydraulic/pneumatic actuators. Themanner of actuation system 200 utilized depends, in part, on the motionthat is to be assisted and the specific weight and performancerequirements for such assisted motion. In accord with some aspectsdirected to assistance with walking, the actuator system 200 utilizes abattery, or a plurality of batteries, configured to provide an averagepower output of less than 100 W, which minimizes the weight of the softexosuit 100 actuation system 200, while retaining metabolic benefits.For example, additional mass carried by the user causes a correspondingand predictable increase in the user's metabolism (e.g., at the rate ofabout 0.9% per added kilogram on the back), so minimizing weight of theactuation system 200, when borne by the user, is generally beneficial.

FIG. 11 shows an example of a soft exosuit 100 according to at leastsome aspects of the present concepts. The soft exosuit 100, asillustrated, includes a waist belt 110 connected by connection elements102, 103 through a node 1 to connection elements 104, 105, which are inturn connected to thigh brace 120. The thigh brace 120 is connected to aT-connector 113 by calf straps 107. The soft exosuit 100 can be madeadjustable to accommodate the natural motion of the user and tocoordinate the forces generated by actuation system 200 and the cable142 (see, e.g., FIG. 10A) with that of the forces of natural motion. Asthe user walks, the forces generated by the actuation system andtransmitted to the cable are applied to heel of the user to reduce workthe user's musculature while walking.

During walking and running, the muscles in the leg generate moments(moment forces) at the hip, knee and ankle joints during the gait cyclein order to propel the person's center of mass forward and resistgravity to maintain an upright posture. These moments change inmagnitude and direction over time as they are generated by the musclesaround these joints in order to guide the person from heel strike andweight acceptance through stance to push off and into swing. As noted,the soft exosuit system 100 in accord with aspects of the presentconcepts, desirably times forces generated by the actuation system 200and the cable 142 to supplement the natural moments at the ankle joint,reducing the metabolic burden and improving mobility. In some aspects,the soft exosuit 100 structure extends as well around the hip joint andthe knee joint to provide a beneficial moment at the hip and knee duringgait cycle. When the actuation system 200 retracts the cable 142 andapplies a force on the foot of the user, the sheath 144 also applies adownward force on the T-connector 113 and the soft exosuit 100, whichcan then apply beneficial moments to the hip or knee during the gaitcycle.

In accord with some aspects, forces applied to the T-connector 113 ofthe soft exosuit 100 results in a tension in the soft exosuit betweenthe T-connector 113 and the waist belt 110. Node 1 and the thigh brace120 help to align the tension over the knee and hip to provide abeneficial moment at each joint. For a healthy adult, walking at aself-selected speed on level ground power is, for the most part,generated at the hip and ankle and dissipated at the knee. In turn,muscles consume metabolic energy to generate these moments. As noted,one of the benefits of aspects of the soft exosuit disclosed herein isto reduce the metabolic cost of walking by adding energy at the ankle toassist with plantar flexion during push-off and to assist with absorbingenergy at the hip during late stance and add energy during an even laterportion of stance. Adding energy at the ankle can reduce the muscleactivation needed to generate the large ankle moment and power requiredat push-off and thereby reduce the necessary metabolic cost. To reducethe metabolic cost of walking, the soft exosuit disclosed hereinadvantageously permits natural gait dynamics. In some aspects of thesoft exosuit, the energy applied at the ankle is provided by a cable,which pulls up on the heel and promotes and/or causes plantar extension.The force from the cable sheath 144 is distributed up through theconnection elements of the soft exosuit 100 (see, e.g., FIG. 10A).

The soft exosuit 100 architecture as seen in FIG. 11 connects the waistbelt 110 to a thigh brace 120 (secured to the user's lower thigh), whichis connect to footwear (e.g., boot, shoe, etc.) connection elements 130.The waist belt 110 and thigh brace 120 are connected by connectionelements 102, 103 that interact with node 1 on the front, middle part ofthe user's thigh. The thigh brace 120 and footwear connection elements130 are connected by connection elements 107 and the cable 142, whichapplies the actuator force at the ankle The connection elements 102, 103between the waist belt and node 1 and the connection elements 104, 105between node 1 and the thigh brace 120 can be pre-tensioned, forexample, by pulling the two sides together and connecting them withVELCRO® at desired position or by pulling on one side which passesthrough a slide or buckle on the other side, in order to remove anyslack in the system that would inhibit efficient operation. Pre-tensionin connection elements 104, 105 can be performed, for example, afternode 1 has been secured in place and the thigh brace has been positionedand tightened about the user's thigh. Accordingly, the soft exosuit 100is pre-tensioned between the thigh (thigh brace 120) and pelvis (waistbelt 110) which are both conical in shape and thus provide resistance tothe applied pre-tension.

When the force is applied at the ankle, such as by the soft exosuit 100depicted in FIGS. 10-11, tension is also redirected across the knee andhip joints up the soft exosuit to the pelvis. As the connection elementsare (further) tensioned, they create moments around the hip, knee andankle as well as normal forces on the user at the various points of softexosuit-to-user contact. In accord with some aspects, the soft exosuit100 is advantageously fitted and aligned to the user to ensure thatthese moments and forces do not adversely affect the user's naturalgait, which would cause the user to expend additional metabolic energy.The arrangement of and orientation of the connection elements, nodes andanchor points are selected to create beneficial moments around the jointor joints of interest (e.g., hip, knee and/or ankle) when tension isplaced on various elements of the exosuit.

As a stiffness of the soft exosuit 100 increases, the soft exosuit isbetter able to transfer the actuation forces to the user in a mannerthat provides both the desired level of assistance and minimaldislocation of the constituent components of the soft exosuit (e.g.,nodes, connection elements, etc.). As noted, the soft exosuit 100 isable to advantageously rely on one or more anchor points (e.g., pelvis,shoulders, etc.) to enhance exosuit stiffness, such as by permittingforces to be borne by the pelvis by placing the waist belt 110 on top ofthe iliac crest, which provides an anatomical ledge for distributinginferior and medial/lateral forces. As shown in the example of FIG. 7,the soft exosuit 100 transfers the forces generated in a leg to eachside of the pelvis through connection elements 102, 103, which bothoriginate from node 1. Providing connection elements 102, 103 todistribute forces from node 1 (e.g., of each leg) to both sides of thepelvis, the force from the actuation can be distributed over both sidesof the pelvis, as opposed to the entire actuation force being anchoredon the same side pelvis bone, reducing the peak point force on eachrespective iliac crest, enhancing comfort of the soft exosuit duringuse. Further, using a connecting element (e.g., 103 in FIG. 7)connecting node 1 to the opposite side hip, the soft exosuit can createhorizontal forces as well as vertical forces on the opposite iliac crestdue to the angle at which it attaches to the opposite side hip. Thishorizontal force helps to keep the waist belt 110 from slipping down asit helps bias the waist belt against the top of the iliac crest.

As shown in FIG. 16, the forces on the connection element 1 (waistband)go approximately horizontally around the body, while the forces onconnection element 3 are angled downwardly. The resultant force vectorfrom these two connection elements acting together lies between thosetwo vectors and is approximately normal to the pelvis, which is roundedin this area as observed in the sagittal plane of the body. Pullingnormally to the body enables the connection elements to remain in placewhile applying large loads, and avoids motion in the tangentialdirection which can cause discomfort.

The position of node 1 in FIG. 16 allows the forces coming up from theankle to be routed into one point on each respective leg, which is thenredirected to each side of the pelvis. In accord with some aspects ofthe present concepts, node 1 allows control over the moments that thesoft exosuit 100 generates on the various joints by allowing adjustmentof the connecting elements that connect node 1 to the waist belt 110 toadjust the direction of the forces to the waist belt.

The thigh brace 120 can be configured to maintain tension in the softexosuit 100 by allowing the calf connecting elements 107 (see, e.g.,FIG. 7) to be slightly angled in order to accommodate their positionwith respect to the knee's center of rotation. The calf connectingelements 107 can be connected to the footwear connection element 130 viathe actuator cable 142. The footwear connection element 130 can compriseone or more elements (e.g., strap(s), etc.) which can act as a harnessaround the heel of the footwear (e.g., boot, shoe, etc.). The footwearconnection element 130 can provide a stiff connection with the user'sfoot and distribute forces over the footwear. For example, when anactuator cable 142 exerts an upward force at the footwear connectionelement 130, the force is transferred through a system of connectingelements or materials to the bottom of the foot and the front of thefoot, where an upward force is exerted at the back of the heel and adownward force is exerted on top of the forefoot. The footwearconnection element 130 provides an actuator cable 142 with a stiffattachment point at the heel to effectively apply force at the ankle.The footwear connection element 130 also assists the plantar flexionmoment at push off by transferring the upward actuation force to back ofthe heel and also to the front of the foot where it applies a downwardforce on top of the foot, thus applying forces which assist plantarflexion on both sides of the ankle.

In at least some aspects, the soft exosuit 100 is constructed from flatmaterials (e.g., webbing, fabric, etc.) that are cut or otherwise formedto a predefined size and stitched together. FIG. 12 shows one example ofa flat pattern layout for a soft exosuit according to at least someaspects of the present concepts. The waist belt 110 can be formed insections, which can be overlapped and secured, as with conventional beltsecurement devices, to adjust the waist belt to people with variouswaist diameters. By way of example, the sections or panels shown in FIG.12 can be constructed from one or more layers of rip-stop nylon and afusible interfacing layer or from one or more layers of rip-stop nylonand a layer of foam padding (e.g., 1/16″ to ½″ thick polyurethane orethylene-vinyl acetate (EVA)). The connection elements can beconstructed from, for example, ½″-3″ polyester webbing. In one aspect,the connection elements 102, 103 are formed from 2″ wide polyesterwebbing, while the balance of the remaining connection elements areformed from 1″ wide polyester webbing. Some connection elements (e.g.,distal ends of calf connection elements 107) can be stitched to formloops to facilitate connection to other connection elements orstructures. Buckles (e.g., plastic buckles) can be used to fasten andtighten the connection elements. The thigh braces 120 can comprise onepiece or two pieces and is constructed, in at least some aspects, from astretch twill material (e.g., a cotton-polyester blend) with hook andloop faster (e.g. Velcro®) stitched to one side.

FIG. 13 provides an illustrative example of how the connection elementsof a soft exosuit according to at least some embodiments of the presentconcepts can be arranged and configured. In FIG. 13, the differentconnection elements of the soft exosuit comprise straps and are numberedand named in Table 2, below.

TABLE 2 Strap Number Name/Description 1 Waist Belt Connection Element 2Node 1 To Same Hip Connection Element 3 Node 1 To Opposite HipConnection Element 4 Thigh Connection Element - Lateral 5 ThighConnection Element - Medial 6 Thigh Connection Element To CalfConnection Element - Lateral 7 Thigh Connection Element To CalfConnection Element - Medial 8 Calf Connection Element - Lateral 9 CalfConnection Element - Medial

In FIG. 13, the waist belt is displayed flattened out presenting theside facing away from the user. This view provides an overview of thewaist belt and the connection elements attached directly to it. Inaccord with some embodiments of the invention, the waist belt includes atop belt connection element and a bottom belt connection element thatcan be joined at the ends to a connection element and buckle that enablethe waist belt to be fastened around the waist of the user with foam orother padding arranged between the waist belt and any points of contact(e.g., iliac crest) on the body. Connection elements 2 and 3 of FIG. 13depend from waist belt 110 and connect to a top of node 1, as shown inFIG. 13 and FIG. 14B. Connection elements 4 and 5 of FIG. 13 depend froma bottom portion of node 1 and connect to an upper portion of thighbrace 200. In FIGS. 14A-14B, the soft exosuit shown in part in FIG. 13is shown on a mannequin for illustration.

The waist belt 110 keeps the soft exosuit from being pulled down undervertical force or slipping over the iliac crest due to horizontal forcethat is the result of the angle of the connection elements that attachthe thigh braces to the pelvis portion of the exosuit. The belt is alsoprevented from slipping down due to the tension placed around the pelvisby tightening the waist belt connection element. It accomplishes this bycreating tension around the pelvis where a portion of the belt passes ontop of the iliac crest of the hip bones. The pelvis serves as a supportor anchor point for the forces which are transmitted from theT-connector 113 at ankle up through the connection elements of the softexosuit 100 to the waist belt 112.

In accord with some embodiments, the pelvis has a relatively small rangeof motion throughout the gait cycle compared to other bony landmarks,such as the knee and shoulder. The pelvis has its largest movement inthe transverse plane where it rotates a total of approximately 12°throughout the gait cycle. In comparison, the knee moves approximately50° in the sagittal plane and movement of the shoulders is highlydependent on the user's posture at any given time. Accordingly, inaccord with the present concepts, use of the pelvis is favorable forembodiments of the soft exosuit 110 in accord with the present conceptsthat are directed primarily to gait assistance. The pelvis's range ofmotion and the cyclic nature of the positions of the various legsegments throughout the gait cycle make the distances between the pelvisand various leg segments highly predictable throughout the gait cycle,which help inform selection of appropriate anchor points capable ofmaintaining soft exosuit 100 tension at specific times during the gaitcycle. Further, the pelvis structure defines a ledge to which the waistbelt 110 can be effectively attached to anchor both vertical andhorizontal forces.

The stiffness of the soft exosuit 100 is, in part, determined by thecompliance of the user-soft exosuit interface. The lower the complianceof the interface between the user and the soft exosuit 100, the higherthe stiffness of soft exosuit in operation. By anchoring to a stable andlow compliance feature, the soft exosuit can transmit higher forces tothe body of the user. In addition, the symmetry of the pelvis allows forthe loads to be distributed evenly onto the body of the user. Bydistributing the actuation forces to each side of the body, the normalforces acting on the body from the soft exosuit at any one point can bereduced, helping to minimize the formation of pressure sores, frictionand rubbing and thereby increasing the perceived comfort of the exosuit.As noted previously, in at least some aspects of the present concepts,the actuation forces may also be, or may alternatively be, distributedto one or more other locations on the body (e.g. torso, shoulders,etc.).

In at least one aspect, the waist belt 110 comprises a top beltconnection element and a bottom belt connection element, with the topbelt connection element being disposed over the top of the hip bone(optionally with foam padding provided on the top belt connectionelement at locations where it rests on top of the iliac crest), and thebottom belt connection element disposed to lie just below the iliaccrest. These two connection elements provide, in combination, a stableattachment platform.

The pelvis, at the iliac crest, provides a suitable anchor point forminimizing the compliance of the soft exosuit. As noted, the softexosuit advantageously leverages the geometry of the pelvis, whichprovides a ledge at the iliac crest on which the waist belt may rest.This makes it possible to anchor both vertical and horizontal forces.Horizontal forces can also be resisted by connection elements (e.g.,bottom belt strap) which surround the side of the pelvis. Reducingcompliance allows for a stiffer soft exosuit, which can be useful toeffectively apply forces to it and thus the wearer. As the soft exosuitreaches a certain level of stiffness, it can be useful to protect theuser from the forces being transferred to them via the soft exosuit.Padding, such as layered fabric or foam padding, can be used to spreadthese forces across a greater surface area on the user as well asproviding a damping medium which reduces the impact of these forces.However, this padding can increase the compliance in the system and thuspresents another variable to control to optimize compliance andstiffness to achieve a balance in efficiency and comfort.

In at least some aspects, node 1 (see, e.g., FIG. 7, FIG. 13, 14B) canbe configured as the junction at which the forces resulting from theankle actuation on each respective leg converge and then divide up to bedistributed to each side of the user's pelvis. Adjusting the position ofnode 1 on the user's thigh can be useful to maintain force balance andsoft exosuit 100 tension. The force may be distributed via one or morestraps that attach the thigh braces 120 to the waist belt 110 of thesoft exosuit.

As shown by way of example in FIG. 7 and FIG. 14B, 16, a node (e.g.,Node 1 in FIG. 14B) is placed at the middle of the thigh in the frontalplane, in accord with at least some aspects of the present concepts, andcan be adjusted by connection element 2 and connection element 3, asshown in FIG. 14A. The vertical placement of node 1 on the thigh can beadjusted according to the size of the user and the distance from thenode to the top of the thigh, which varies from user to user, but isgenerally far enough down so that it does not interfere with hipflexion. Proper vertical placement can be verified by having the userwearing the soft exosuit flex their hip after the node position has beenset to see whether it interferes with hip flexion. The placement of thenode can be used to optimally align and adjust the force paths in thesoft exosuit 100 which, in accord with some aspects of the presentconcepts, can prevent or reduce problems associated with the thigh brace120 rotating due to force imbalances. Improperly aligned force paths cancreate unwanted moments at the hip and knee which can result inunnatural motion, muscle fatigue and soreness. Through the use of node 1(see, e.g., FIG. 13,14B, 16), the forces resulting from the ankleactuation are transmitted in a controlled and linear path from the ankleto the front of the thigh, where it can be further distributed to eitherside of the pelvis. With the connection elements passing into onejunction (node) in this way it allows for the tension paths around thehip and knee to be adjusted more coherently by tightening, loosening orrepositioning the connection elements on the exosuit. This enablesgreater control and fine tuning of the moments that the soft exosuitgenerates at the hip and knee throughout the gait cycle.

In accord with some embodiments of the invention, the particularconfiguration of soft exosuit utilizing node 1 helps to achieve a muchhigher exosuit stiffness than would otherwise be achievable since itanchors the force path to each side of the pelvis, where it is possibleto achieve a much higher exosuit stiffness. The use of node 1 enablesthe soft exosuit 100 to distribute the forces over the pelvis, where thestiffness of the waist belt was far greater, resulting in the softexosuit being able to maintain higher forces while suffering very littledisplacement. The connection elements connecting node 1 to the waistbelt 110 can be secured to the node's position as they are constrainedin the medial, lateral and vertical directions. Connection elements 4and 5 (see, e.g., FIG. 16) can be tensioned to establish a pretension inthe soft exosuit between the waist belt 110 and thigh brace 120 thatincreases the soft exosuit stiffness through pre-loading it downwardlyagainst the pelvis and upwardly against the thigh. Correct pre-loadresulting from tensioning connection elements 4 and 5 can beaccomplished by creating, qualitatively, a snug tension across the frontof the thigh that can be adjusted according to the user's comfort, whichcan vary from user to user.

In accord with at least some aspects of the present concepts, the waistbelt 110 (see, e.g., FIG. 7) functions optimally when tension ismaintained in the waist belt. If the waist belt 110 is not properlytensioned, the soft exosuit 100 will sag when actuation is applied.

Proper vertical placement of the waist belt 110 is desirable to maintainproper soft exosuit stiffness. In accord with some embodiments of thepresent concepts, the soft exosuit 100 utilizes the iliac crest on thepelvis as an anchor for the majority of the forces acting on the user.If the waist belt 110 is not supported by the iliac crest then the softexosuit 100 may not be able to provide as much initial stiffness, unlessit is supported by other features of the body. If the waist belt 110position is set too low, or becomes too low during use, it couldinterfere with the hip motion of the user, causing discomfort (e.g.,soreness of the hip flexors) and decreasing soft exosuit functionality.

During evaluation of aspects of the soft exosuit, it was found by theinventors that tension created across the hip during early to mid-stancecould lead to muscle fatigue in the hip flexor and gluteus mediusmuscles. In early to mid-stance, the hip is flexed and, thus, to createa moment that will resist this flexion, tension is required to pass frombehind the hip's center of rotation, below it, and to the front of thethigh. Thus, if connection element 2 in FIG. 13 or FIG. 14B passes belowthe hip's center of rotation, it could create such moments. There aretwo possible ways that could lead to connection element 2 creating thesemoments. The first is that node 1 is positioned too low on the thigh.The second is that connection element 2 attaches further behind thewaist belt. Connection element 2 can be attached directly to the waistbelt (e.g., via Velcro®) once node 1 (see FIG. 13 or FIG. 14B) ispositioned correctly with respect to the center of the thigh. Once node1 is correctly placed, it can be secured by attaching connection element2 to the waist belt 110 by extending connection element 2 in a straightline from node 1 to the waist belt (i.e. making sure that the connectionelement remains smooth and flush with the wearer), ensuring thatconnection element 2 has a proper angle of attachment to the waist belt.Generally, node 1 can be laterally positioned in the center of thethigh, about 10 cm inward of the pelvis (e.g. iliac crest), directlyabove the patella and vertically positioned just below the creasebetween the thigh and torso. Connection elements 2 and 3 can each extendangled upwardly from this point to the side of the pelvis (side of theiliac crest), on the same side and opposite side of the body,respectively. Outer connection element 2 can be angled between about40-65° with respect to the horizontal and connection element 3 can havea correspondingly smaller angle with the horizontal.

If node 1 is placed in an incorrect horizontal location, it will resultin a disadvantageous rotation of the exosuit. As shown in FIG. 17B, ifnode 1 is placed either to the left or to the right of the middle of thethigh, tension in the soft exosuit will then be unbalanced with respectto the symmetry of the leg. In this case, node 1 is constrained byconnection elements 2 and 3 and thus will be secured in its position.Connection elements 4 and 5 will begin to exert a rotational force onthe thigh brace when the soft exosuit 100 is actuated because of theforce path being directed to one side of the leg's line of symmetry orthe other as opposed to being in-line with the leg's line of symmetry.The rotation is caused by the thigh brace 120 being pulled to whicheverside the imbalance is on when the soft exosuit 100 is actuated. When thesoft exosuit 100 tension releases after the actuation, the thigh brace120 settles back down on the user, but does not go back to its originalposition as it has now translated slightly in a direction toward theimbalance. This will repeat for every actuation cycle until connectionelements 4 and 5 have regained symmetry with node 1. At that point thethigh brace 120 will have rotated such that the calf connection elements107 no longer align correctly with the knee's center of rotation, suchthat the soft exosuit now creates incorrect moments on the user.

In at least some aspects of the present concepts, node 1 is placeddirectly in the center of the thigh several centimeters below theflexion point of the thigh, as is shown by way of example in FIG. 17A.The approximate vertical position can be determined by having the wearerflex their hip once the node has been positioned to sec if the node 1interferes in any way with their hip flexion. Nominally, node 1 isplaced close to the flexion point, but not so close that it interfereswith hip flexion. Node 1 should be horizontally positioned in the centerof the thigh, as horizontal misalignment could cause the soft exosuit torotate undesirably. Once node 1 is positioned correctly with respect tothe thigh, it is first secured by attaching connection member 2 to thewaist belt by extending it in a straight line from node 1 to the waistbelt, this ensures that connection member 2 has a proper angle ofattachment to the waist belt, second connection member 3 is loopedthrough node 1 buckle and attached, using care to ensure that, whensecuring connection member 3, the node center position does not shift.Vertical placement of node 1 is not as critical to the soft exosuit'sfunction as the horizontal placement. If node 1 is positioned too highup on the thigh it will interfere with the user's hip flexion and willbe apparent.

In accord with some embodiments of the present concepts, the thigh brace120 can wrap around the lower thigh. In one aspect, the thigh brace 120comprises two pieces that are joined together, the front piece which canhave a hook and loop fastener (e.g., Velcro®) facing towards the userand a back piece which can have a hook and loop fastener (e.g., Velcro®)facing away from the user. The calf connection elements 107 can besandwiched between the two layers and secured in place by the hook andloop fastener (e.g., Velcro®).

In accord with at least some embodiments of the present concepts, thebottom of the thigh brace 120 is placed between approximately 3-6centimeters (and preferably between about 4-5 cm) above the top of thepatella, as shown in FIG. 18, but this distance can vary depending onuser's physiology. Preferably, the thigh brace 120 is positioned higherto allow for a greater range of adjustability for the calf connectingelements 107. For a skinny to medium sized user with low to moderatemuscle mass, the thigh brace 120 can be positioned 4 centimeters abovethe patella. For users with larger thigh diameters, the thigh brace 120can be positioned 5 or 6 centimeters above the patella to permit correctpositioning of the calf connecting elements 107. Thus, the position ofthe thigh brace 120 above the knee can be selected to provide for properplacement of the calf connecting elements 107, which are attached to thethigh brace 120, and to ensure that the calf connection elements 107 donot interfere with the knee's range of motion. Furthermore, with thethigh typically having a larger diameter further up the leg, this allowsthe calf connecting elements to avoid contacting the knee area, therebyavoiding chafing in the knee area.

As shown in FIG. 19, the location and angle at which the calf connectingelements 107 exit the thigh brace 120 can be adjusted. Thisadjustability permits a user to adjust the soft exosuit to accommodatetheir particular physiology and musculature while positioning the calfconnection element 107 appropriately relative to the knee's center ofrotation. Adjustments to the placement of the calf connection elements107 with respect to the knee's center of rotation are used to ensure thecorrect moments are produced at the knee.

In accord with some embodiments of the invention, the thigh brace 120can contribute to exosuit stiffness by balancing the horizontal loadwhen the soft exosuit is tensioned. This horizontal load can be a resultof the loading path of the soft exosuit being angled slightly as ittravels up from the ankle to the pelvis, such as is shown in FIGS. 19and 20A-20B. A change in direction occurs at the thigh brace 120 toaccommodate the correct placement of the calf connection elements 107with respect to the knee's center of rotation. The correct placement ofthe calf connection elements 107 is desirable because a tension iscreated across the knee joint when the soft exosuit is actuated.Depending on where the calf connection elements 107 are positioned withrespect to the knee's center of rotation, the moment generatedresponsive to this tension can either help or hinder the user. In orderfor the soft exosuit tension to not adversely affect the user's naturalknee moments, the tension can be in line with or slightly in front ofthe knee's center of rotation at the time of actuation. The position ofthe calf connection elements 107 on the thigh brace 120 and the angle atwhich it exits the thigh brace 120 can be adjusted so that the tensionis in-line with or in front of the knee's center of rotation.

FIG. 19 shows the tension in the lateral calf connection element 107 asa force is applied at the T-connector, the same is occurring to themedial calf connection element 107 on the other side of the leg (notshown). FIGS. 20A-20B show how the forces on the medial and lateral calfconnection elements 107 converge at the thigh brace 120. The calfconnection elements 107 are each coupled to the thigh brace 120 via asecure attachment (e.g., Velcro®). The direction of the force acting onthe calf connection elements 107 acts to pull them apart from one otherand puts tension on the fabric between the two calf connection element107 attachment points to the thigh brace 120. The resulting tensionprofile is shown in FIG. 20A by horizontal vectors in FIG. 16A, with thehighest tension (largest vector) in the thigh brace 120 being at thebottom of the thigh brace 120, with decreasing tension (smaller vectors)with increase in height from the bottom of the thigh brace. It ispossible that, for some users, the horizontal force will reverse sign atthe top of the thigh brace 120 as the force profile depends on both thedirection of the force being applied and how the calf connectionelements 107 are angled with respect to the thigh brace 120.

The calf connection elements 107 can attach to the thigh brace 120 andjoin together in the back of the shank below the bulk of the calfmuscle. The junction where the two straps meet below the bulk of thecalf muscle is a point at which the Bowden cable sheath 144 can beattached to the soft exosuit 100. As noted, in at least some aspects ofthe present concepts, the calf connection element 107 length, angle, andlocation of connection to the thigh brace 120 can all be adjusted toaccommodate users of different physiologies. In some embodiments, thereare four adjustment factors that provide for correct placement of thecalf connection element 107, and an overarching objective for each ofthese variables is to position the calf connection elements 107correctly with respect to the user's knee center of rotation. The firstfactor is the location at which the calf connection elements 107 exitthe thigh brace 120 (FIG. 20B), the second is the angle at which thecalf connection elements 107 exit the thigh brace 120 (FIG. 19), thethird is the vertical position of the thigh brace above the patella(FIG. 18), and the fourth is the vertical location of the Bowden CableT-attachment with respect to the shank (FIG. 21).

The factors noted above can be adjusted with respect to the thighcircumference and the thigh length of the user. Where embodiments ofsoft exosuits in accord with at least some aspects of the presentconcepts enable such variability in one or more of these factors (e.g.,in a suit designed or fitted for a specific user, the soft exosuit maynot need to provide for such subsequent adjustability), the optimalplacement of the calf connection elements 107 is such that, when thecalf connection elements 107 are tensioned, they do not cause moments atthe knee that will negatively impact the user's natural gait cycle. Oneway to ensure the calf connection elements 107 do not cause moments atthe knee that will negatively impact the user's natural gait cycle is tohaving the tension pass through the knee's center of rotation, thusensuring that the soft exosuit creates no moments on the knee. However,since the knee flexes and extends through a wide range of motionthroughout the gait cycle, with a constantly changing instantaneouscenter of rotation, this approach is difficult to realize. Another, morepractical, way to achieve this end is to permit creation of moments thatdo not negatively impact the user's natural gait.

To further illustrate correct calf connection element 107 placement, anunderstanding of knee and ankle dynamics is helpful. In at least someaspects of the present concepts, a soft exosuit configured to assistwalking movement is actuated during the terminal stance phase andpre-swing phases that occur from approximately 30% of the gait cycle to62% of the gait cycle. At the beginning of terminal stance (30% gaitcycle) the gastrocnemius (calf muscle) and soleus (inner calf muscle)gradually increase their contraction to counter the growing plantarforefoot flexor moment, as well as to store elastic energy in the muscleand tendon tissue to rebound during heel lift/push-off, that occurs asthe body is falling forward. This action increases as the ankle beginsto plantar flex as the heel comes up and the pivot point moves to theforefoot. Additionally as this is happening, the knee flexion reachesits lowest point (about 5° at 40%). This reduction in flexion occurs asthe body's mass is now falling forward on the forefoot that places theforce vector of the falling body in front of the knees center ofrotation causing passive extension of the knee. However this extensionis resisted by posterior muscle action, i.e. the gastrocnemius that isalready tensing due to the action at the knee and ankle as well as thepopliteus that lies across the knee joint. As the minimum flexion angleis reached (40% gait cycle) the knee immediately begins to flex as atthat point the knee joint will have moved in front of the body vectordue to the heel rising. At this point, the posterior muscles that wereacting to resist knee extension are now promoting knee flexion as wellas the body vector that is now posterior to the knee's center ofrotation and thus passively promoting knee flexion. Terminal stance endswith initial contact of the contralateral limb (50% gait cycle). Withthe onset of pre-swing (50% gait cycle) the weight is shifting over tothe other leg allowing the knee to flex freely that results from theelastic recoil of the Achilles tendon, the action of the posteriormuscles and the passive action of the body vector being posterior to theknees center of rotation. However, if knee flexion occurs too rapidlythen the rectus femoris comes on to decelerate the knee causing anextension moment at the knee, thus the extension moment during pre-swingis not always present and is dependent on how rapidly the leg goes intoflexion.

From the above description, three points are to be made about thetension of the soft exosuit across the knee joint during the actuationphase. First, if such tension is present in front of the knee's centerof rotation between 30 and 40% of the gait cycle, this will cause theposterior muscles (gastrocnemius and popliteus) to work even harder toreduce the decrease in flexion. This creates a feeling of “too muchtension” from those wearing the exosuit, which can be remedied by movingthe calf connection elements 107 to a more posterior position on thethigh brace 120. Second, if the tension is in front of the knee from 40to 50% of the gait cycle, this will resist knee flexion that, at thatpoint, is occurring passively due to the body vector being behind thecenter of rotation as well as actively due to the posterior muscles. Atthis point, it would be beneficial to dispose the calf connectionelements 107 either in-line with or behind the knee's center of rotationas disposing them in front of the knee's center of rotation would likelyoverwork the posterior muscles. Third, if the tension is in front of theknee from 50 to 62% of the gait cycle, it will be resisting the knee'sflexion motion that is occurring passively due to the recoil of theAchilles tendon, as well as the direct muscle action of the posteriormuscles. Although the knee's flexion moment is sometimes resisted by therectus femoris during pre-swing, this is not always the case and theextension moment that may be expected for this portion of the gait cyclemay not necessarily occur.

By observing the moments and corresponding movements of the knee andanalyzing results of extensive laboratory testing of differentconfigurations of the soft exosuit, the present inventors developedconfigurations of the calf connection elements 107 that are, or can be,tensioned so as to create moments that do not impede the user's naturalwalking cycle for a wide range of user physiology. A first challenge todetermining appropriate soft exosuit connection element positioning(e.g., to achieve an optimal balance of weight, power, metabolic effect,comfort, and variability of different physiology, to name a few) wassimply large person-to-person dimensional variances. A second challengewas the rate at which the knee goes from being extended to flexing rightaround push off (50% gait cycle), which is close to the end of theactuation phase. If the strap migrates behind the knee's center ofrotation too early, this would cause unwanted flexion moment that wouldimpede the user's natural gait. At this point, it can be beneficial tohave the calf connection elements 107 migrate to be either in-line withor behind the knee's center of rotation to avoid adversely affecting theuser.

In accord with some embodiments, the desired placement of the calfconnection elements 107 is shown in FIGS. 23A-23B, which avoids theproblems noted above by having their line of action pass through theeffective center of rotation of the knee when the wearer is in anupright standing position. This position can be determined by findingthe junction between the femur and tibia on each side of the tibia andby observing the surface anatomy, with the appropriate position beingidentified by a bone protrusion on the femur and tibia respectively,between which is a “valley” or depression which runs in theanterior-posterior direction. If looking at the knee from the side, thelocation that the calf connection elements 107 will nominally passthrough is approximately 30%-40% of the distance from the back side(posterior) of the knee. For some people, this is exactly the case. Forothers (e.g., large people, muscular people) the correct placement isdetermined on a case-by-case basis using an approximation and trial anderror approach.

FIGS. 24A-24B show an actuation phase over one gait cycle for oneembodiment of a soft exosuit 100 in accord with aspects of the presentconcepts. The actuation phase 190 is highlighted on both the knee moment(FIG. 24A) and range of motion (FIG. 24B) graphs. The left portion 191represents when the soft exosuit 100 creates an extension moment aroundthe knee and the right portion 192 shows when the knee creates a flexionmovement around the knee. Desirably, the moments the soft exosuit placeson the wearer mirror those naturally created by the wearer (i.e.,moments about the joint(s) that equal as closely as possible the naturalbiological moments during motion). In situations where joint momentsfrom the soft exosuit 100 may be reversed from a natural moment for themovement at a given time, the soft exosuit 100 desirably minimizes themoment arm about the joint (e.g., to make the knee moment as small aspossible by putting the connection elements 107 through the knee centerof rotation).

As shown in FIG. 25A, the calf connection elements 107 terminate at theT-connector 113 where the Bowden Cable sheath 144 (not shown) connectsto the soft exosuit. In accord with some embodiments, the T-connector113 is positioned below the bulk of the calf muscle. The calf muscle iscompliant and protruding and, accordingly, if the T-connector 113 isplaced on it at the time of actuation, it will dig into the musclethereby increasing the compliance in the system and causing userirritation. The space below the calf muscle is much less compliant andalso allows the calf connection element 107 to descend down the shank ina straighter path as opposed to being angled more deeply to accommodatethe calf's bulk. If the calf connection element 107 descends the shankat a greater angle with respect to the vertical, this makes the softexosuit's force path less efficient, as it now wants to straighten whenit is tensioned.

FIG. 25A shows forces acting on the calf connection elements 107 from aside view according to some embodiments of the present concepts. Thedotted-line vectors 200 (the upper and lower arrows) represent theactuation force path, the solid lines vectors 201 represent the reactioncomponent forces at the bottom of the calf connection element 107 andthe T-connector and at the top where they exit the thigh brace 120. Thedotted line vectors 202 acting along the calf connection elements 107represent the tension in the illustrated calf connection element 107resulting from actuation. The horizontal component forces 203 that acton the user are also shown.

FIG. 25B shows the T-connector placement with respect to the calf of thewearer. FIG. 25C shows the difference in angles with respect to thevertical with respect to the vertical placements (1) and (2). The largerangle resulting from placement (1) will have the effect of creating alarger horizontal force component that will cause the T-connector topush into the wearer's calf. Correct positioning of the calf connectionelements 107 contributes to the overall compliance in the system bycircumventing the bulk of the calf muscle. The area below the calfmuscle is mostly skin and bone and thus provides relatively lowcompliance. Circumventing the calf muscle also allows the calfconnection elements 107 to descend the shank in a straighter line withrespect to the vertical. If the calf connection elements 107 terminatedon top of the calf, two adverse effects would follow. First, the calfconnection elements 107 would descend the shank at a greater angle withrespect to the vertical, making the soft exosuit's force path lessefficient as it would want to straighten when tensioned. Second, due tothe calf's compliance, the tendency for the calf strap to straightenwith respect to the vertical will result in the T-connector 113 digginginto the calf, which will reduce the stiffness in the soft exosuit asthe actuator will need to compensate for this additional displacement.The T-connector 113 at the end of the calf connection elements 107 canbe positioned correctly with respect to the horizontal by positioningthe T-connector 113 directly in-line with the center line of the heel.In order to position the calf connection elements 107 correctly withrespect to the vertical, the connection elements are adjusted such thatthe T-attachment gets positioned at the top of the footwear (if worn) ornominally so that the T-connector 113 is located below the bulk of thecalf muscle, which allows the calf straps to successfully circumvent themushy bulk of the calf. In accord with some embodiments, some of themore rigid components can be replaced with softer more compliant ones.

The footwear connection element 130 provides a stiff interface with theuser's foot. It at least some aspects, the footwear connection element130 takes the form of a harness disposed around a boot, as shown by wayof example in FIGS. 26A-26C, which respectively depict side, rear andbottom views of such boot. FIG. 27 (side view) shows the threeadjustment points provided on the exemplary footwear connection element130 depicted, with the adjustment points 1-3 being circled with a whitedashed line. Table 3 below shows the function of each adjustment point.The footwear connection element 130 relays the upward force due to theactuation at the heel to the front of the foot where it applies adownward force as seen in FIG. 28A. Transferring the upward horizontalforce to the front of the foot in such a way helps to promote ankleplantar flexion by virtue of the complimentary moments that aregenerated. FIG. 28B shows the force path on the footwear connectionelement 130 on the bottom of the boot.

As to the positioning of the connection members, connection member 1 inFIGS. 26A-26C wraps around the middle of the footwear as shown. Itshould be placed in the groove between the heel and the fore-foot. Theconnection member 1 must be secured by an attachment mechanism (e.g.,Velcro®) to prevent slippage. Connection member 2 comprises a widesection in the example shown and is connected to a central portion ofconnection member 1 on top of the foot. Connection member 3 wraps aroundthe ankle, as shown, providing a constraint to keep the footwearconnection element 130 from slipping off the heel and being tensionedupwardly to provide greater stiffness. Connection member 4 constrainsthe footwear connection element 130 from slipping medially andlaterally. The bottom edge of connection member 4 may be advantageouslyplaced about 0.5 cm about the edge of the boot at the back. Thispositioning of connection member 4 will result from correct positioningof node 2. Connection member 5 is the actuator cable attachment pointand connection member 6 transmits the actuation force to the heel. Node2 is desirably placed as close to the bottom of the heel as possible inthe vertical direction and directly in the middle of the heel in themedial-lateral direction. Node 3 is placed slightly behind the middle ofthe foot-sole and its position is dictated by the placement of node 2.

In one example of a method of donning the boot attachments correctly,Node 2 is first placed on the heel, and then connection members 1 and 6,shown in FIGS. 26A-26C, are placed under the boot in their correctposition as shown. At this point, it is likely effective for the wearerto stand up on the boot, securing connection members 1 and 6 in place.With these connection members held in their nominal positions,connection member 1 is adjusted as needed (e.g., tensioned/loosened),then connection member 3 is adjusted as needed (e.g.,tensioned/loosened), and finally connection member 4 is adjusted asneeded (e.g., tensioned/loosened), in that order.

TABLE 3 Boot Strap Function 1 Constrains the boot attachment to thefront of the boot as well as transfers the forces from the actuation tothe front of the foot where it pulls down on connection member 1. Thisdownward force in the front of the foot also contributes to creating amoment about the ankle joint. This mechanism helps to increase thestiffness in the system that makes lifting the heel more effective. 2Wide webbing to spread the forces acting on the top of the foot asconnection member 1 tensions across the front of the foot 3 Providesconstraint to keep attachment from slipping off the heel. By keepingconnection member 3 tensioned ensures stiffness in the system by pre-tensioning the boot attachment in the vertical direction such that whenthe cable begins to pull there is little to no slack in the bootattachment. 4 Constrains the attachment from slipping medially andlaterally. 5 Cable attachment 6 Transmits force from actuation to heelNode 2 Connects connection member 3, 4, 5 and 6. This point acts toequalize the forces on the boot attachment to avoid the footwearconnection element 130 from slipping when the soft exosuit is actuated.Node 3 Connects connection member 1 and 6. As the force from theactuation tensions connection member 6 the tension gets relayed throughNode 3 to connection member 1 where it travels up the sides of the bootand creates a downward force at the top of the foot.

In another embodiment, the footwear connection element 130 can comprisea sock-like structure that can be donned, much like a sock (see, e.g.,FIGS. 26D ₁-26D₅, 79). Optionally, the footwear connection element 130comprises one or more fasteners that may be adjusted (e.g., bytightening or cinching, such as by using VELCRO®, etc.) to secure thefootwear connection element around the wearer's foot. Alternativelystill, the footwear connection element 130 can comprise a step-intostructure that may then be folded over to envelop the foot, at whichposition one or more fasteners tightened or cinched (e.g., VELCRO®,etc.) to secure the footwear connection element 130 around the wearer'sfoot. An example of such a footwear connection elementl30 is shown inthe panels of FIGS. 26D ₁-26D₅, which shows views of an in-bootattachment to the foot, shown with the foot at a neutral position (FIG.26D ₁), foot in plantar flexion with the attachment taut against thefoot (FIG. 26D ₂), and foot in dorsiflexion with the attachment slack(FIG. 26D ₃) and, at the bottom, views of foot attachment showing itsconstruction (FIGS. 26D ₄-26D₅). The footwear connection element 130 ofFIGS. 26D ₁-26D₅ is a simple textile-based structure, in which webbingextends under the wearer's heel and over the forefoot. As shown, thewebbing attaches with VELCRO® over the forefoot, but this could be sewnto be a single piece. The footwear connection element 130 of FIGS. 26D₁-26D₅ comprises a connection element configured to connect around thewearer's ankle that can be used to hold the footwear connection elementin place.

FIGS. 26E-26G ₂ show aspects of another embodiment of soft exosuitfootwear attachment 130 according to at least some aspects of thepresent concepts. The designs noted in FIGS. 26A-26C focused on afootwear connection element 130 in the form of a harness disposed overboots or shoes which provided a connection point to the Bowden cable 142actuator. These solutions are “out of boot” solutions on which the cable142 pulls to create a force on the boot heel upward with respect to theheel. For a footwear connection element 130 that utilizes an “inside theboot” force actuator (such as shown in FIGS. 26E-26G ₂) to createmoments about the ankle joint, two parts are utilized, a cable attachedinsole and a cable guard. In order to apply forces to the wearer, acable must extend into the wearer's shoe or boot with one end fixed tothe actuator external to the shoe (A) and the other affixed an objectinternal to the shoe under the wearer's foot (B) insole, such as isshown in FIG. 26E.

In another aspect, a plastic or foam element 131 is optionally insertedin between the webbing 133 over the forefoot and the wearer's foot todistribute the pressure over the top of the foot more evenly than if thewebbing was used in isolation, such as is shown by way of example inFIG. 26G ₁. In another aspect, a midsole 132 can be combined withwebbing (and optionally foam or plastic as previously noted) over thetop of the foot and/or ankle, to provide additional paths for torque totransfer to the foot, such as is shown in FIG. 26G ₂.

Attaching a cable or webbing at the rear part of an insole element 130,such as shown in FIGS. 26E-26F, provides a method of fixing point B suchthat forces applied to a point on the cable or webbing are transferredto the wearer's heel proximal to the ankle joint in the sagittal plane,this creating torque around the joint. This insole can either be apartial or full insole. It may be desired that the insole have somestiffening elements such as carbon fiber to distribute load to the heel.If stiffening elements are used, the insole could advantageously besegmented to allow for maximum range of motion on the ball of the foot.A cable guard is provided (see, e.g., FIG. 26F) at a rear portion of thelower leg. For actuation, the cable needs to retract. In situationswhere the cable is compressed between the boot and wearer's leg abrasioncould result as well as loss in efficiency due to friction between thecable wearer and boot. Thus, a system that provides an open channel forthe cable to freely move is desirable.

Once secured to the wearer's foot, the sock-like footwear connectionelement 130 would then be connected to the soft exosuit 100 via aconnection element (e.g., webbing) that attaches to the top of thesock-like structure and goes directly up to the bottom of the calfconnection elements 107. In yet another embodiment, the footwearconnection element 130 comprises a heel cup configured to wrap aroundthe heel (e.g., the wearer's heel, a heel of the footwear). In stillanother embodiment, the footwear connection element 130 comprises aninsole insert that goes into the footwear under a portion of thewearer's foot (e.g., the heel) or the entire foot, such insole insert,or the aforementioned heel cup, attaching at a rear portion and/or rearlateral portions to a connection member (e.g., webbing) that exits thefootwear and attaches to the soft exosuit actuator cable. Desirably, anyconnection members disposed within the footwear comprises a low frictionsheath, low friction coating, or low friction material so as to minimizefriction against the wearer. In yet another aspect, the footwearconnection element 130 comprises a sole insert that goes under a portionof the sole of the footwear (e.g., just the heel) or the entire sole ofthe footwear. A connection member (e.g., webbing, cable, etc.) isprovided at a rear portion and/or rear lateral portions of the soleinsert to connect to a connection member attaching to the soft exosuitactuator cable.

In accord with some embodiments of the invention, an actuator 200 canalso be used to reduce the metabolic cost of walking (or other movementsor activities) while wearing a soft exosuit 100 in accord with thepresent concepts. The actuator 200 is used to supplement forces of thedesired moment, such as (for walking), supplementing forces about theankle during the toe push-off portion of the gait cycle when the anklemuscles are generating the greatest power. To perform this action, byway of example, a motor can be used to create the necessaryforce/displacement on a Bowden cable 142 and sensors 150 can be used tosense joint position and determine actuation timing.

The actuator 200 generates a force that can be transmitted to the user'sfootwear (e.g., a boot) using a cable to change the distance between apoint on the user's boot and the bottom of the soft exosuit (see, e.g.,FIGS. 21-22). With a minimally extensible soft exosuit, this contractingdistance generates a tensile force in the soft exosuit 100, footwearconnection element (e.g., boot attachment), and cable 142. This tensileforce can be applied at a position offset from the axis of the anklejoint and result in a moment about the joint.

As one example, flexible Bowden cables 142 can be used by the system 100to transmit forces from actuator(s) in an actuator unit 200 to the softexosuit 100. Rigid and/or heavier actuator(s) 200 can be mountedremotely or distally (e.g., on a backpack away from the lower body),such as is shown in FIG. 10A.

In at least some aspects of the present concepts, each limb (e.g., leg)can be driven by its own actuator unit 200, which may comprise one ormore actuators. In yet other aspects of the present concepts, each jointcan be driven separately by its own actuator unit 200, which maycomprise one or more actuators. In still other aspects of the presentconcepts, a plurality of joints can be driven by an actuator unit 200,which may comprise one or more actuators.

In one embodiment in accord with the present concepts, each actuatorunit 200 includes a drive motor 222 and a pulley module 224, such as isshown in FIG. 29. The actuator unit 200 is used to drive a Bowden cable142 and to sense the user's gait by measuring heel strike contact (Seefoot switch, FIG. 30). The Bowden cable 142 is attached to a pulleywheel 225 in the pulley module 224 and is extended and retracted byrotation of the pulley wheel 125. In accord with some embodiments, thedrive motor 222 includes gearing (e.g., a gear box as shown in FIG. 29)to increase the drive torque of an output shaft coupled to the pulleymodule 224 to drive the Bowden cable 142 that provides the assist to theuser's motion. In other aspects, the motor 222 is connected directly tothe pulley module 224 without intermediate gearing.

The drive motor 222 advantageously comprises an encoder (not shown) orother positional sensor configured to indicate the rotational positionof the motor output shaft. The drive motor 222 (and encoder if provided)are connected to a motor controller 228 used to control the power, speedand direction of the drive motor 222. In accord with some aspects of thepresent concepts, a centralized motor controller is provided to controlmore than one motor. Alternatively, each actuator unit 200 includes itsown resident system controller 226 configured to receive sensor inputsand to communicate with the motor controller 228 to control theoperation of the drive motor 222 for that actuator unit. The systemcontroller 226 (or optionally centralized motor controller) can includea computer or microprocessor-based system, such as, but not limited to,those based on the PC/104 standard. The drive motor 222 is coupleddirectly or indirectly (e.g., through a gear train) to the pulley module224 comprising a pulley wheel 225 engaging the proximal end of theBowden cable 142.

The pulley module 224 comprises a housing 230 adapted to engage theBowden cable sheath 144 such that, when the pulley wheel 225 is rotatedin a first direction, the Bowden cable 142 wraps around the pulleycausing the distal end of the Bowden cable 142 to be retracted into thedistal end of Bowden cable sheath 144 and, when the pulley is rotated ina second direction, the Bowden cable is unwound from the pulley, causingthe distal end of the Bowden cable 142 to extend from the Bowden cablesheath 144. In at least some embodiments, the pulley 225 is enclosed inthe housing 230 such that, when it is rotated in the second direction,the cable 142 is driven out and can apply an extension force.

As noted above, in at least some aspects of the present concepts, asingle actuator unit 200 can be used to provide energy to one or morelimbs and/or one or more joints. As one example, alternating powertransmission to separate limbs may be accomplished via a clutchswitching power transmission between the limbs, which takes advantage ofthe out-of-phase movement of opposing limbs (e.g., the legs aretypically out of phase during walking).

The control system 226 is configured to sense or determine the gait ofthe user and actuate the drive motor 222 to pull on the Bowden cableduring specific times of the gait cycle or to actuate another actuationsystem configured to introduce forces at specific times of the gaitcycle (or other movement). Actuating the drive motor 222 at predefinedpoints during the gait cycle can create a predefined tension in the softexosuit 100 that applies a force about the ankle that aids in walking.One or more sensors worn by the user (e.g., one or more foot switches,one or more joint angle sensors, etc.) are provided to transmit signalsto the control system 226 enable the control system 226 to synchronizethe motor actuation with the user's gait cycle (or other movement). Inaccord with various embodiments of the invention, the sensor can takemany forms, including sensors that sense the angular position ofspecific joints. See, for example, commonly owned WO 2013/044226 A2,which is hereby incorporated by reference in its entirety. In accordwith some aspects, the sensors comprise a pressure sensor or a simpleon/off switch that senses the pressure of the foot during the gaitcycle, e.g., a heel-strike.

In accord with other aspects of the present concepts, one or moresensors can take the form of EMG sensors that sense muscle activation atspecific locations. The pattern and scale of these activations caneither determine gait cycle (pattern) or amount of assistance required(based on scale). Other sensors that detect joint position, relative orabsolute, either with respect to ground or respect to a point on thewearer, may be used to determine gait pattern and, therefore, can beused to control actuator activation. Other sensors can include, but arenot limited to, hyper elastic strain sensors, accelerometers, inertialmeasurement units, internal measurement Units (IMU) and/or Goniometersensors. These sensors, or other sensors, singly or in combination, candetect motion indicative of body position. Depending on the sensor(s)used, heuristics specific to that system are able to be developed todetermine when the muscles in the body are applying force to a joint(e.g., such as the ankle, knee, or hip) so that the soft exosuit 100can, in turn, be configured to apply force at the appropriate time andin proportion to the estimated muscle force. For example, one possiblescheme would be to estimate the dynamics of the user's body byestimating velocities of each of the joints and, using an approximaterigid body model of the wearer, estimating torques at each joint, fromwhich appropriate tension to produce resultant, beneficial torques aredetermined.

An alternate scheme would involve recording EMG measurements and sensorssimultaneously in a training phase. After this data is collected,machine learning algorithms are used to predict when the muscles arecontracting, as a function of the sensor inputs. Then, in practice, theEMG sensors would not be used, and instead the trained algorithm wouldpredict muscle activation based on the sensors, and apply tension to thesoft exosuit when the appropriate muscles would be activated.

Another scheme would involve directly measuring the muscle activationusing EMGs, sensors which detect the muscle diameter, or some othermeans. Then, the soft exosuit 100 could be tensioned in proportion tothe activation of certain muscles or combinations of muscles.

In accord with some embodiments of the invention, one or more footswitches are positioned between the foot and sole of the boot to senseheel strikes to provide measurement of the rate of the user's gaitcycle. The foot switch or sensor is used to detect the moment when theheel of each foot first hits the ground during the gait cycle, and thecontrol system 226 uses the signal from the foot switch to calculate thegait period. The position of the ankle at any point during the gaitcycle can be estimated based on a known ankle position vs. time curve(assuming level ground and a nominal gate). The estimated ankle positioncan be used to determine when to retract the Bowden cable 142 andtension the soft exosuit 100. The tensioned soft exosuit 100 can providea moment about the ankle during the toe push-off portion of the gaitcycle to supplement the muscle supplied forces and reduce the energyexpended by the user.

In some aspects, Velcro® or some other attachment mechanism is used toconnect one portion of the soft exosuit 100 to another after beingmanually pulled to a desired tension. For example, node 1 (see, e.g.,FIG. 7) can be connected to the waist belt 110 and to the thigh brace120 using connecting elements have Velcro® fasteners. For example, inFIG. 16, connecting elements 4 and 5 loop through buckles on the thighbrace 120 at the bottom and then can be pulled upwardly and fasteneddown upon themselves with Velcro® or other fastening component(s).Alternatively, connecting elements 2 and 3 can each be secured at thewaist belt 110 with Velcro® directly, without looping through buckles,or by another fastening member or element. Another option is to use apiece of webbing passing through a feed-through buckle preventing itfrom backing out after it is tensioned, and manually pulling taut theprotruding end of the webbing.

In accord with some aspects, a force sensor is used to continuouslymeasure the tension in each Bowden cable 142. An idler pulley 232 (see,e.g., FIG. 29, 30, 34) is biased against the Bowden cable 142 and a loadcell 234 (see, e.g., FIG. 29) can be used to sense the cable 142tension. These measurements are logged and used to automatically tensionthe soft exosuit to an appropriate level. In accord with some aspects,the soft exosuit controller(s) (e.g., system controller 226) detects anincrease in the tension of the soft exosuit due to natural body motionand applies actuation based on this signal. In one aspect, the softexosuit controller(s) continuously monitor the force in the exosuit.When the soft exosuit is tensioned to some small amount because ofgeometric changes in the user's position, the controller(s) can sensethat (small) force and actuate the soft exosuit to increase or decreasethe tension, as appropriate. For walking, soft exosuit tensioning can beaccomplished, for example, by applying a constant offset to the motorposition signal from the control system 226 (e.g., PC/104).

In some aspects, the actuator unit 200 is configured to communicate witha local or remote external computer (e.g., a desktop or laptop computer,tablet or a smartphone) over a communication channel, such as Ethernet(e.g. wired or wireless—WiFi), Blue Tooth, I2C, or other open orproprietary communication channel. The external computer can be used,for example, to boot-up the actuator system control program upon firstpower up, adjust control parameters such as exosuit tension, executediagnostic checks, transmit software, or even remotely control theactuator unit 200. In at least some aspects, the control system 226automatically boots on power-up and receives control inputs fromswitches on the exterior of the actuator unit 200 or on a hand heldwired or wireless remote control or electronic device (e.g., smart phoneapp). In other aspects, the control system operates autonomously basedon preprogrammed algorithms that detects or anticipates the intent oractions of the user and applies appropriate assistance.

In at least some aspects, as shown in the example of FIGS. 29-30, theactuator unit 200 is controlled by a Diamond Systems Aurora single boardcomputer 250 in a PC/104 form factor connected to a Diamond SystemsMM-32DX-AT analog and digital I/O expansion board. The PC/104 computer250 can be powered from a 4-cell (14.8-16.8V) Lithium Polymer batteryvia a Diamond Systems Jupiter power regulation board. Of course, it isexpected to utilize improved processors (e.g., faster, smaller, etc.) aswell as smaller and lighter batteries and/or batteries with higher powerdensities as technology improves. FIGS. 29-30 show an example of apulley module 224 and drive box 223, in accord with one aspect of thepresent concepts. Tension in the Bowden cable 142 can be sensed with a50 kg beam-style load cell 234 (Phidgets, product code 3135) mountedagainst an idler pulley 232 in the pulley module 224. A full bridgestrain gauge on the load cell 234 is connected to a signal amplifier 242(e.g., Futek CSG110) through an electrical interface (e.g., pogo pin).Each amplifier/load cell pair is calibrated by adjusting the output ofthe amplifier 242 while applying known loads to the load cell 234. Theamplifier 242 outputs a DC voltage from 0-10V corresponding to the forceon the load cell 234. This voltage is read by an analog input pin of theMM-32DX-AT. The amplifiers 242 can be powered by the PC/104's 14.8Vbattery via their own on-board power regulators.

In accord with some aspects of the present concepts, the heel strikescan be sensed with foot switches 150 (FIG. 30), such as foot switchesfrom B&L Engineering (product code FSW). The foot switches 150 can befoot-sole-shaped force sensitive resistors. The terminals of the heelportion of each foot switch 150 are connected to ground and a digitalinput pin of the MM-32DX-AT respectively, as shown in FIG. 31. A 1 kΩand a 10 kΩ resistor in parallel between each foot switch digital inputand a +5V rail can pull the digital pin up. When a heel strike occurs,the resistance between the two terminals of the foot switch 150 drops,the voltage at the digital pin decreases to approximately zero, and thechange in state can be read by the MM-32DX-AT I/O board. The foot switch150 can be wired to a 3.5 mm audio jack, which plugs into a stereo cableand to a corresponding 3.5 mm audio jack in the pulley module 224. Theelectrical connection to the foot switch 150 can be passed through thepogo pin interface to the PC/104 computer 250. The audio jack permitseasy disconnection of the foot switch from the rest of the exosuit,which facilitates donning and doffing of the soft exosuit 100.

FIG. 32 shows the connections to the PC/104 computer 250 and MM-32DX-ATI/O board according to some embodiments of the invention. The PC/104computer 250 is connected to control switches on the outside of thedrive box 223. Power switches are provided for each drive box to breakthe positive voltage lines of the PC/104 and motor controller batteries.Two momentary toggle switches and a rocker switch provide user input tothe control algorithm running on the PC/104 computer 250. The rockerswitch can be used to engage the walk mode of the control algorithm andthe momentary toggle switches can be used to rotate the left or rightmotor to tension the soft exosuit prior to walking. These three userinterface switches are connected to digital input pins on the MM-32DX-ATwith 10 kΩ pull-up resistors and share a common ground with the PC/104.When each switch is activated, the digital input is connected to groundand the pin pulled low. In addition to, or in the alternative to, thebox mounted switches, a small hand-held wired or wireless remote (notshown) can be provided. The remote's switches can be connected inparallel with the box's switches and provide duplicate functionality. Inaddition to, or instead of, the user input switches, other userinterface systems can be integrated into the soft exosuit, includingvoice controls, a touch screen, wearable computer, or a heads-up-display(e.g., Google glasses or wearable display with retinal sensing or otherinput, such as a wirelessly connected track pad or softkeys).

In accord with some embodiments, the motor 246, motor encoder 248, andmotor controller assembly is shown in FIG. 33. Each EC-4pole 30 Maxonmotor 246 is connected to a Copley Controls Accelnet Panel ACP motorcontroller 260. A HEDL 5540 3-channel encoder 248 with 500 counts perturn with RS-422 digital signaling is used for feedback. Each motorcontroller 260 can be powered, by way of example, by two 4-cell(+14.8-16.8V) lithium polymer batteries in series for a total of+29.6-33.6V. The motor controller 260, in the example shown, suppliesthe motor with up to +24V. The Accelnet Panel motor controller 260 canaccept a DC voltage between −10 and 10V to change the angularorientation of the pulley and tension or slacken the cable 142. A −10Vsignal can move the pulley one full rotation in the counter-clockwisedirection from the starting point upon power up and a +10V signal canrotate the pulley clockwise one full rotation. In accord with someaspects, the negative voltages are not used, since in operation themotor controllers 260 are powered on only when the cables 142 areextended out as far as possible. In software, the control signal can belimited to being positive to prevent damaging the system by running themotors into the physical stops.

The control voltage can be generated from one of the analog out pins ofthe MM-32DX-AT. To ensure smooth motor operation, the voltage signal issent through a low pass filter. This filter can include an RC singlepole construction with R=68Ω and C=47 μF, and provide a cutoff frequencyof 48.9 Hz. The signal can additionally be filtered by the motorcontroller, which implements a digital filter operating on the analoginput.

In accord with some aspects of the present concepts, each pulley module224 include one or more indicators, such as a blue, green and/or red LEDwhich illuminate to indicate various states of the system status (e.g.,green illumination when the pulley module is correctly connected to thedrive box 223). The power and ground for the LED(s) can passed throughthe pogo pin interface from the PC/104's battery. A 1 kΩ resistor can beused to bring the voltage from the battery down to a suitable drivingcurrent.

In accord with some aspects of the present concepts, the Bowden cables142 are grounded via the metal pulley box 224 and drive box 223 shell,which serves as the ground for the circuitry inside. Grounding theBowden cable 142 advantageously prevents the Bowden cable from actinglike an antenna and transmitting electrical noise to the load cells andother components of the system.

In accord with some aspects of the present concepts, the actuator unit200 uses a 200 W brushless motor 222 (which operates at a reduced dutycycle) to move the pulley 225 and cable 142 through the assistancetrajectory. The pulley 225 converts the motors torque and rotationalspeed to a force and displacement that can be applied through the cableto the ankle (FIG. 34).

The assistance provided by the actuator unit can be limited, forexample, by motor supply power, which was 100 W in the soft exosuitsunder test, but is not a functional limitation. In the tested softexosuits, the duty cycle of the motor 246 provided up to approximately200 W for a portion of the cycle, then returning to a low power draw forthe remainder of the cycle while maintaining an average powerconsumption at or below a working 100 W requirement selected for testing(FIG. 35).

In accord with some aspects of the present concepts, the EC-4pole 30brushless motor 246 by Maxon Motors can be used because it is a highefficiency motor that provides high power to weight ratio and a compactsize. Other motors can be used depending on the performance requirementsof the system. While a rotary motor was used in various of the aboveexamples, other actuators can also be used including, but not limitedto, electro-mechanical actuators (e.g., motors, solenoids, etc.),pneumatic actuators (e.g., pneumatic cylinders, McKibben type actuators,etc.) and hydraulic actuators (e.g., hydraulic cylinders, etc.). In yetother aspects of the present concepts, different types of motors can beutilized (e.g., high torque and low speed) that require no gearhead andconsequently provide reduced weight, reduced noise and improvedefficiency.

Further, while preceding examples disclose the cable actuator 142 systemas comprising a pulley system 224 controlling movement of a Bowdencable, other actuators may advantageously be used with the soft exosuit.By way of example, any actuator capable of shortening the length of acable or cord connected between two points having a sheath (Bowdencable) or not (Free cable described above) can be used. These actuatorscould be placed anywhere on or off the person, depending on the movementto be assisted, the context of such motion, contraindications, and theavailability of alternative actuation placements. The actuator(s) may bedistally located (e.g., in a backpack borne by the user's shoulders)with a proximal end of the actuator power transmissions element (e.g.,cable) attached to a suitable location of the soft exosuit system (e.g.,footwear attachment element 130) as described above. Alternatively, oneor more actuator(s) may be disposed in between anchor points, connectionelements and/or nodes, or over a portion of the length between terminalends of the cable. Examples of other types of actuators can include oneor more pneumatic or hydraulic linear actuators, pneumatic of hydraulicrotary actuators, ball or lead screw actuators, belt or cable drivenactuators.

In accord with other aspects of the present concepts, actuators whichreduce the length between the terminal ends are used and include one ormore semi-passive actuators, such as a magnetic or mechanical clutch.These actuators would engage at a point in the gait where the lengthbetween points is shorter then when assistance should be given (e.g.,when the knee is bent). In conjunction with a retractable length ofcable such that it has a minimum level of tension, the clutch would lockthe length at shorter state such that when the leg naturally extended,force would be generated due to the stretch in the soft exosuit andcable. This would be classified as a semi-passive system and would beexpected to require a lower energy level than active systems.

In accord with the other aspects of the present concepts, variousmechanisms can be used to adjust the tension in the soft exosuit. Insome embodiments, the same mechanism that actuates the soft exosuit canalso be used to adjust the tension in the exosuit. In other embodiments,a separate mechanism can be used to tension the soft exosuit, singly ortogether with an actuator. The soft exosuit can be actively shortenedusing an actuator which reduces the length between two points on thesuit. One mechanism that could accomplish this is a motor pulling on aBowden cable, the sheath of which is connected to one point on the softexosuit and the center of which is connected to a different point on thesuit. This can be accomplished using, mechanical pneumatic, hydraulic,or other actuators.

Of course, as previously noted, the tension may be adjusted manually atone or more points by physical adjustments to the relative positions ofthe connection elements, anchor points, and nodes (e.g., adjustingstraps using buckles and/or Velcro®, tensioning a drawstring, wire orcable and locking it in place, etc.). As another example, the wearercould pull on a webbing strap passing through a locking buckle, whichsecures the webbing strap after release. In another example, the wearercould pull on a piece of webbing (e.g., a connection element) and securethe webbing with Velcro® to a part of the suit.

The wearer could also pull on or otherwise tension a cable passingthrough a ratchet mechanism (e.g., a rotary ratchet mechanism, such asmade by made by Boa Technology Inc., disposed on the waist belt 110) orlockable spool configured to secure the cable in place at a set tension.The ratchet mechanism or spool it attached to one end of a Bowden cable(e.g., at a top of the cable where the ratchet mechanism is hipmounted), the other end of which was connected to two locations on thesoft exosuit to reduce the distance between them, with interactingelements (e.g., pawl element, ratchet element) providing releasablesecurement. The wearer could also advance a ratcheting mechanism byrotating a central hub around which a cable is wrapped, or could tensionthe soft exosuit with a screw mechanism that is then locked into thefinal position. Tension can be released by pushing a button to releasethe interacting elements of the ratchet mechanism (e.g., to move a leveraway from ratchet gear teeth). The ratchet mechanism or spool can eitherbe turned manually (to tension or de-tension) by the soft exosuit weareror by an actuator, for example a geared motor. Even where a soft exosuitis not being actuated as an assistive system, the soft exosuit may stillbe worn in a tensioned mode. In various configurations, the ratchetmechanism can be located at the wearer's waist or hip (so as tofacilitate adjustment while walking or running), near the ankle, orpotentially elsewhere on or about the wearer's torso.

In accord with some embodiments, a mechanism to tension the soft exosuitcan include a screw element. In one aspect, a carriage element isconnected to an end of a Bowden cable and is configured to move up anddown by means of a threaded portion in which a screw element isdisposed. A support structure holds the carriage element in placerelative to the cable sheath, and a top portion of the screw is exposedto the user to permit rotation of the screw. Rotation of the screwcauses a linear movement of the carriage and the attached Bowden cableend, thereby increasing or decreasing, respectively, a tension in thesoft exosuit. An optional locking element in provided to minimize thepotential for loosening of the setting. In one aspect, the screw couldbe controlled by a small motor or other actuator to turn the thread, inwhich case no locking element would be needed.

As previously noted, the soft exosuit can optionally be activelytensioned (e.g., cable shortened or lengthened) is accord with a programas the user of the soft exosuit moves. Alternatively, in other aspects,the soft exosuit is automatically tensioned using one or more actuators,and maintained at one or more set tension(s) (e.g., a fixed value, afixed range of values, different values or ranges of values fordifferent portions of movement, a nominal average value, a nominal peakvalue, etc.), the set point(s) of which could be adjusted by the user.In this respect, the system is configured to sense the tension in thesoft exosuit to provide appropriate inputs for the controllercontrolling the tension.

With all of these mechanisms, the soft exosuit can be made to beloose-fitting on the wearer by releasing these tensioning mechanisms,such as to facilitate doffing of the soft exosuit. Such tensioning (ordetensioning) devices permit a user, for example, to retain a firstlevel of tension between certain points on the soft exosuit and a secondlevel of tension (higher or lower than the first tension). The softexosuit advantageously comprises multiple tensioning mechanisms capableof operating simultaneously.

During the gait cycle, the motor(s) 246 can operate over a range oftorques and speeds to achieve the desired cable 142 trajectory. Sincehigher motor efficiencies occur at high speeds and low torques, someembodiments of the invention can select a combination that includes amotor with a pulley and gearbox that keeps the motor operating as closeto maximum efficiency as possible during the gait cycle.

In accord with some embodiments, the Maxon EC-4pole 30 has a nominalcontinuous speed of 15,900 RPM. However, for this embodiment, the motoris limited by the max speed of the encoder: 12,000 RPM. An alternativeencoder (MR, Type ML, 500 CPT, 3 Channels, with Line Driver Maxon#225778) can be used in the actuator system would increase the maximummotor speed.

In accord with some embodiments of the present concepts, a better motorfor this system would have a lower nominal continuous speed for highertorques. A lower operating speed would reduce the number of necessarystages in the gearbox and would result in a higher overall efficiency.

In accord with some embodiments of the present concepts, the pulley 225and gearbox 244 convert the motor's fast rotation into cable 142lengthening and shortening movements of the pulley wheel 225. The pulleywheel 225 and the gearbox 244 together determine the maximum cabletravel and the maximum cable speed for given load states. The pulleywheel 225 diameter and the gear reduction can be determined by workingbackwards from the minimum cable travel needed and the maximum cablespeed required to meet the biomechanics and exosuit stiffness needs. Thetotal amount of assistance was driven by these two limits, as well asthe power budget.

In accord with some embodiments of the present concepts, the pulleywheel 225 can be a single wrap design, while in other embodiments, thepulley can be a multiple wrap design. With a single wrap design, thepulley wheel 225 circumference cannot be less than the cable traveldistance. In accord with some embodiments, the cable travel can be basedon the soft exosuit 100 architecture and biomechanics of walking of theuser. In accord with some embodiments, the cable travel can includethree lengths: cable pull length, exosuit tension length, and a marginof safety to prevent bottoming out. In accord with some embodiments, thecable travel was given a significant safety length due to uncertainty indesign parameters and user variability. The cable pull length and thecable tension length were measured from the soft exosuit and previousactuator system with participants ranging in height from 5′8″ to 6′5″.The three lengths and calculated pulley diameter can be seen in Table 4.

TABLE 4 Cable pull length (Lp) 8 cm Length needed to assist foot giventhe lever arm to the back of the boot + the soft exosuit stiffness Cabletension length (Lt) 5 cm Length needed to tension the soft exosuit priorto walking. Takes up slack in the system due to wearer differences Cablesafety length (Ls) 7 cm Length needed at the end of travel to preventbottoming and to accommodate various sized people or added pull lengthTotal Length (Lcirc) 20 cm Pulley diameter 70 mm Distance overcircumference multiplied by working revolutions

In accord with some embodiments of the present concepts, the use of asingle wrap pulley resulted in a usable angle of 340° (0.94 revs). Theselected pulley diameter of approximately 70 mm provided appropriatecable length. In general, a larger pulley and a larger bend radiusprovide less wear and reduced cable stress.

In accord with some embodiments of the present concepts, the gearbox 244is chosen to meet the maximum speed required during cable pull andrelease when assisting the ankle. As seen in FIG. 36, the cabledisplacement for maximum assisting case can be treated as a triangleoperating over the active portion of the cycle. The leading line is thecommanded motor position signal in units of centimeters and thefollowing line is the resultant motor position as measured by the CME-2motor controller software scope. A positive displacement corresponds toa retraction of the cable and the delay between signal command and motormovement stems from acceleration limit of the motor controller.

As seen in Table 5, which shows gear reduction calculations in accordwith at least some aspects of the present concepts, the maximum cablespeed was found to be 37 cm/sec for the given pulley diameter (70 mm)and maximum motor speed. From the maximum cable speed, the necessarygear reduction was found to be 107:1 and a gearbox with a reduction of111:1 was selected.

TABLE 5 Variable Value Gait Cycle (T) 1 sec Duty cycle (p₁-p₂) 40% to83% Length of pull and release over 8 cm duty cycle (Lp) Maximum cablespeed (V_(cable)) 1Lp/T(p₂ − p₁) = 37 cm/s Pulley diameter (D) 7 cm Maxmotor speed limit 12000 RPM Gear reduction (R:1) R =(M_(speed)/60)/(V_(cable)/L_(circ)) = 107 Selected gearbox reductionClosest gear reduction is 111:1

It is desirable for the motor to operate within its speed-torque curveand that forces applied during high speed pulls do not exceed themotor's limits to preserve the life of the motor.

In accord with some embodiments of the present concepts, a Bowden cableis utilized that includes an inextensible cable translating inside aninextensible sheath. The Bowden cable 142 transmits forces from theactuator unit 200 to the ankle (via forces transmitted to a footwearconnection element 130). The Bowden cable sheath 144 is attached to thesoft exosuit and actuator unit 200 and the cable 142 is anchored to thefootwear connection element 130 (FIGS. 21-22). In other embodiments,webbing or cables can be routed through guides in the fabric.

In accord with some embodiments of the present concepts, many types ofBowden Cables can be used in the system. In addition to standard Bowdencables, non-standard and similar operating cables, such as Nokon® brandcables can be used. The Nokon® cables can provide increased efficiencyover traditional Bowden cables. The more efficient cables enable morepower to be delivered to the ankle per a given input power. This canprovide an advantage for a system with a limited power budget. The woundwire cable in the Nokon® system is 1.5 mm in diameter and has a maximumtensile strength of 2200 N.

FIG. 37 shows the end fittings on the Bowden cable 144. These ferruleend fittings 146 can integrate with both the actuator unit 200 and thesoft exosuit. A T-connector can be created which interfaces with thesoft exosuit through sewn in loops at the calf straps and the bootattachment. In other embodiments, an alternative to the T-connector canbe a VELCRO® attachment, a buckle. In some embodiments, the T-connectorcan be removed and a continuous webbing with adjustable slider used inits place. Ferrules on the ends of the cable can both engage the pulleyand secure the cable to the lower T-connector. These ferrules can alsoact as mechanical fuses, coming off the cable when a predefined force(e.g., 600-650 N) is applied to the T-connector—thus providing a safetyfeature that limits the force that the system can apply to the user. Atthe proximal end, the Nokon® cable can include an extended aluminumhousing which can be fitted into a hole on the pulley module and can besecured by a set screw. Other end fittings for the Bowden cable caninclude, for example, a button tab. In some embodiments, a rivet orgrommet can be provided in the webbing, which allows the cable to passthru while restraining the outer sheath. In some embodiments, acompression fitting clamps the outer sheath to webbing.

In accord with some embodiments of the present concepts, the currentsystem tension in the cable can be input to the control system for datalogging and pre-tensioning the soft exosuit prior to walking. Sensingtension in the cable can also be used in a gait control algorithm. Thepulley module's load cell can be mounted to a small idler wheel whichdeflects the cable by a small angle as it passes from outside the box tothe pulley. In general, the force required to deflect the cable for an8° cable angle increases linearly with the tension in the cable, asshown by reference numeral 167 in FIG. 38. The general range of systemtension in the current embodiments of the pulley system 224 arerepresented by the operational envelope 166, showing a load cell forceof approximately 150 N and a cable tension of about 500 N. A 50 kg beamload cell can be used along with an 8° bend angle to measure the fullrange to cable tensions possible with the system. Reference numeral 168represents the cable breaking strength.

In accord with alternative embodiments of the present concepts, FIGS.39-40 show the differences between a series mounted and parallel mountedforce sensor and a hybrid combination. The deflecting idler wheel 232geometry can be used instead of an inline force sensor setup (see seriesforce sensor 275 in FIG. 39 and FIG. 40) because the idler wheel doesnot limit the cable travel. However, the inline-series sensor 275 canprovide direct measurement of force and can be placed at or near theankle, which would remove measurement error due to friction in theBowden cables 142. Another embodiment is to have a force sensor (e.g.,275) located at the distal end of the Bowden cable sheath 144 attachedto the Bowden cable sheath and the connection element. This would allowfor unlimited cable travel and a superior measurement due to the distallocation of the sensor.

In accord with some embodiments of the present concepts, a B&LEngineering foot switch can be mounted in the boot and provides theright sensitivity for an average adult person (foot switches mayoptionally be optimized for a user's weight or operational weightranges). When not compressed, the foot switch has a nominal resistanceof a few hundred mega-ohms, creating an effective closed circuit. Theresistance drops down to 14Ω during heel strike (around 300 lbs. offorce), a value much less than the 909Ω pull-up resistance (1 kΩ inparallel with 10 kΩ), which pulls the PC/104 digital pin low. The 1 kΩresistor was added in parallel with the 10 kΩ resistor to minimizeon/off toggling during transitional motions, such as when the heelstrikes and when the heel is lifted up.

As configured in the tested configurations of soft exosuits, a DiamondSystems Aurora PC/104 computer 250 having a 1.6 GHz Intel Atom CPU, 2 GBof RAM was used and booted MS-DOS with a real-time kernel from a 4 GBSSD disk. The MS-DOS installation can be configured to launch an xPCTarget binary executable on startup. The xPC Target application waitsfor a connection from the host computer, receives a compiled programfrom MATLAB/Simulink on the host computer, and executes the program. TheAurora PC/104 can be paired with a Diamond Systems MM-32DX-AT I/Oexpansion board to provide 32 analog inputs, 4 analog outputs, and 24digital pins assignable as inputs or outputs. In accord with someembodiments of the present concepts, the PC/104 xPC Target combinationprovided a useful amount of processing power and flexibility. The PC/104has a desktop CPU capable of 48.2 FLOPS and 2 GB of RAM, and controlalgorithms can be developed for use in the invention without worryingabout speed or memory. The small size and low power consumption make thePC/104 suitable for use in a portable system. In accord with someembodiments of the present concepts, the Copley Controls Accelnet PanelACP motor controller is a high performance controller capable ofvelocity control and position control. It has numerous command inputs(RS232 serial, CAN, PWM, analog voltage). The Copley Controls softwareallows basic auto-tuning and calculations of controller gains.

In accord with some embodiments of the present concepts, a Futek CSG110was used as a general purpose amplifier for the full bridge straingauges. The Futek CSG110 has DIP switches for setting excitation voltageand the mV/V sensor range as well as rotary potentiometers forcalibrating the zero point and span of the DC voltage output to eachparticular load cell. The Futek CSG110 amplifier allows the load cellsto be interfaced with the PC/104.

In accord with some embodiments of the present concepts five batteriesare used to power this system. Four Gens Ace 14.8V 4S1P 5000 mAh 40Clithium polymer batteries are used to power the motor controllers andmotors, two per drive box (one drive box per limb). Each pair ofbatteries is wired in series in order to supply the motor controllerwith 29.6V DC. The fifth battery is a lithium polymer Gens Ace 14.8V2S1P 4000 mAh 25C that is used to power the PC/104 computer, both Futekamplifiers, pulley module LED's, and a cooling fan in each drive box.The PC/104 battery can share a common ground with the motor controllerbattery pairs and every component in the system. Batteries in accordwith some embodiments of the invention could be an attachment to thesystem. These batteries could be contained in a housing with a terminalconnector contacting at least 2 electrical connector blades capable ofcarrying greater than 200 W. These blades could interface with matingconnector inside the motor hosing to form a power connection capable ofpowering the motors. The battery housing and motor housing could havemating retaining features such as latches to secure the housings makinga quick release interchangeable system.

Lithium polymer batteries were selected because they provide acceptableperformance in this application. Lithium polymer chemical constructionprovides one of the highest energy storage to weight ratios and is morerobust and safer than lithium ion. In other embodiments of theinvention, the soft exosuit may include energy harvest elements (e.g.from sun, wind, natural body motion, body heat, vibration, inductivecoupling with a charging station, corded Li battery charging port, etc.)to reduce the overall battery size required to power the suit.

In accord with some embodiments of the present concepts, the pulleymodule shown in FIG. 29 can be made of the five parts. The pulleyhousing 230 can provide the mechanical structure to support the pulleymodule 224 and comprises a pulley housing (e.g., aluminum) having aninner shell (e.g., Delrin) and an outer shell (e.g., Delrin). The pulleyhousing 230 resists loads created by the pulley on the Bowden cable,provides additional support to the motor shaft, aligns and attaches thepulley system to the drive box, optionally includes a window that allowsvisual inspection and movement of the pulley system, optionally includesa guide slot or channel that retains cable in an enclosure to allow pushand pull cable actuation, optionally provides a stop to preventover-rotation or backwards rotation of the pulley, optionally attachesto the drive box by two screws that allows for “quick release” removalof the pulley module sub system, and provides secondary bearing surfacefor the pulley when pulley module is detached from drive box. Theprimary bearing surface is provided by the motor shaft, and when thepulley module is detached from the drive box, the pulley flanges can besupported by mating housing surfaces. In another example, a bearing canbe centrally located under the pulley cable groove to reduce momentforces perpendicular to the axis of rotation. This centrally locatedbearing would be fixed to the pulley housing via a cantilevered surface.This configuration allows for minimal side force to act on the motorbearings. Additionally, the pulley module could use latches to secure itto the motor housing and provide a quick release mechanism.

The pulley wheel 225 guides the cable 142 and can include some or all ofthe following additional features: 1) number/color markings to giveabsolution position in the view window for trouble-shooting purposes, 2)weight reducing webbing to provide a light weight design to reducepulley inertia, 3) ferrule capture screws to keep the cable in placeduring push and pull actuation, 4) a stop pin to interact with thepulley housing to limit pulley travel.

In accord with some embodiments of the present concepts, the motormount, while considered part of the pulley module, can be located in thedrive box and provide locating and fastening points for the pulleymodule to be secured to the motor in place on the drive box.

In accord with some embodiments of the present concepts, the controlscheme can include the process of deciding how to move the motors basedon the input from the sensors. The control scheme can be implemented inthe code that runs on the PC/104 embedded computer. In accord with someembodiments, the control scheme can be written in Simulink blocks andMATLAB code. Simulink blocks for the MM-32DX-AT analog expansion boardcan handle input and output (e.g., I/O). One Simulink block can be usedto read values for all the sensors and another Simulink block can beused to send the position values to the motor controllers. AdditionalSimulink blocks can be used to capture data and save it to the PC/104'sdisk or send it to a host computer for saving or debugging. The bulk ofthe processing can be accomplished by a MATLAB script embedded in aSimulink block. This MATLAB script can use the foot switch states, userinterface buttons, and the current time step to calculate the desiredmotor positions. In accord with some embodiments of the invention, theSimulink block diagram can run at a fixed time step of 0.001 seconds (1millisecond) on the PC/104.

In accord with some embodiments of the present concepts, the motor 246outputs for each leg can be calculated from a trapezoidal trajectory,generated prior to runtime. This trajectory has a unit width and avariable peak height corresponding to the level of actuation desired(e.g., a pulse with a 4 cm amplitude, a pulse with a 6 cm amplitude).The cadence of the user's gait can be calculated from the timing betweenmultiple heel strikes. In particular, the gait period can be recordedfor a predefined number of steps, for example, the previous 20 steps,and the average taken. A twenty step moving average proved sufficientfor a low pass filter. This average gait period can be used to scale thetrapezoidal trajectory across one full gait cycle for each leg. Each legcan be treated independently and the waveform for each leg can becalculated independently. In some embodiments, both legs can be treatedthe same and the same calculated waveform can be used for each leg.

Upon heel strike, the control scheme can use a look-up table to generatethe required motor pull. The flat trajectory from 0-40% of the GaitCycle (GC) acts as a delay, keeping the soft exosuit slack as the footis planted on the ground and the user's hip pivots into position abovethe foot. Starting at 40%, the motor pulls the cable in and tensions thesoft exosuit to the maximum level at 62.5% GC when toe off occurs. Aftera period of holding, the motor then unwinds the cable back down to zeroat 83% GC and resets for a new cycle.

The trajectory can be limited by the physical performance of the motor246, gearbox 244, and Bowden cable 142. The downward slope of thetrajectory can be bound by the maximum slew rate of the motor.Additionally, the motor controller can limit the maximum acceleration ofthe motor to 2500 rotations/sec2 and the maximum velocity of the motorto 11500 rpm, effectively rounding the sharp corners of the trapezoidaltrajectory and shifting it slightly (˜3%) to the right. Finally, thistrajectory can be generated based on ankle position vs. time charts thatbegin when the heel first touches the ground. The foot switches used inthis system require a significant amount of pressure to trigger and thusa heel strike is not sensed until the heel is on the ground and theuser's weight has begun to load the foot. This occurs at somewherebetween 2-6% in the nominal gait cycle, most likely 2-3%.

In accord with some embodiments of the present concepts, the userinterface switches are provided on the outside of the drive box 223, ona handheld remote, or via a wireless device, to modify the way thecontrol scheme functions. When the walk switch is disengaged, thecontrol scheme can optionally continue to run, but does not output pulsesignals after heel strikes. Each tension toggles adds or subtracts anoffset to the motor positions looked up from the trapezoidal trajectory.The offset grows in magnitude depending on how long a tension toggle isheld down.

In accord with some embodiments of the present concepts, the value ofthe force sensors can be data logged and used to adjust the magnitude ofthe trapezoidal trajectory, but not used to calculate the desired motorpositions. In accord with some embodiments of the invention, the forcesensors can be incorporated in a feedback loop to follow a desired forcetrajectory throughout the gait cycle instead of desired motor position.

In accord with some aspects of the present concepts, a direct line cablecan be used instead of a Bowden cable. A direct line cable can include afree cable from the actuator to the point of action. This will create aforce in line with the cable between the two end points. In accord withother aspects of the present concepts, a multi-point cable system isused. For example, a multi-point cable system can include a free cablefrom the actuator 120 that passes through angle transition points alongthe path to the distal end and transfers forces and displacements alongits length through some or all of the transition points including theend. Moments about each joint between the ends of the cable depends ontheir location with respect to the transition points of the free cable.The cable or webbing can be configured to slide with respect to thetransition points and the wearer, unlike the Bowden cables where thecable is shielded until exiting the end. A multi-point cable and/ordirect cable can include one or more of a wire or filament rope,webbing, such as the soft exosuit material, an elastic element (e.g.,rubber) or any other flexible force transmission element.

In accord with some embodiments of the present concepts, the Bowdencable 142 system can be replaced by a solenoid or other type of actuatordisposed remotely (e.g., in a user-borne backpack) or locally (e.g., onan assisted limb, such as a thigh-based actuator used to add energy tothe knee or ankle or a gastrocnemius-based actuator to add energy to theankle, etc.). In accord with some embodiments, a hydraulic pistontransducer can be used. In this embodiment, a linear piston couldreplace the lower portion of the Bowden cable and can be connected viahydraulic tubing to a source of hydraulic pressure and flow. Thetransducer would include a cylinder and a piston that would reduce itslength to actuate the exosuit. In an alternative embodiment, a pneumatictransducer, such as a McKibbon actuator, could be replace the lowerportion of the Bowden cable and be connected via pneumatic tubing to asource of air pressure and flow. The transducer could include a cylinderand piston or an inflatable bladder which would reduce its length wheninflated.

The cable actuator described includes a motor driven a pulley systemwhich connects to a Bowden cable. Other actuators could be used in placeof the motor. Alternative actuators can include actuators or motorswhich can be used to shorten the length of a cable or cord connectedbetween two points having a sheath (Bowden cable) or not having a sheath(e.g., free cable). These actuators could be placed at the proximal endas described or in some cases over a portion of the length between theterminal ends of the cable. These actuators can include one or morepneumatic or hydraulic linear actuators, pneumatic of hydraulic rotaryactuators, ball or lead screw actuators, and belt or cable drivenactuators.

In accord with some embodiments of the present concepts, Textile basedforce sensors can be used to measure linear displacement of woven fabricwebbing between two points A and B. This linear displacement measurementcan be combined with the properties (e.g., elastic properties) of thewoven substrate to a calculated force measurement. The force can bemeasured along the collinear line formed by points A and B andterminating at the end points of that line where fabric meets otherconnectors. Woven webbing generally provides a strong durable fabrictypically made in ribbon form (e.g., length, width, and thickness).Applying force linearly along the length of the fabric causes a stretch(strain) in the fabric. This stretch has been measured and is relativelyconsistent such that a force applied to the fabric will result in aspecific strain measurement. Using this property the textile based forcesensor can calculate the force based on the measured strain. In orderfor this to work properly the sensor must be able to measure strains inabout the 0.05-5% range as well as have a very low stiffness. The needfor the 0.05-5% range is based on material properties of webbing. Theneed for the low stiffness is so that the force sensor will notcontribute significantly to the webbing stiffness.

In accord with some embodiments of the present concepts, the textilebased force sensor can be used to aid in control of one or more exosuitactuators. The force measurement combined with actuator positionmeasurements and force displacement profiles can be used by the controlsystem to detect motion and provide feedback. It also aids in determinecorrect position of suit elements (via a stiffness measurement)

In accord with some embodiments of the invention, textile based forcesensor can be used for recoding of forces in the soft exosuit elementsduring any activities, to aid in development by measuring forces inspecific areas of the soft exosuit, to detect injury by measuring jointangles, and to detect joint angles either for control or data analysis.

In accord with some embodiments of the present concepts, the sensors canbe placed at various locations on the soft exosuit. In one aspect, asurface based sensor is adhered to or attached to a connection element(e.g., woven webbing fabric) or other element at two points along alength of the connection element or other element. In another aspect, afull surface sensor is adhered to or attached to a connection element(e.g., woven webbing fabric) or other element at two points over an areaof the connection element or other element. In another aspect, a pocketis formed in or woven in (for a woven material) a connection element orother element and a sensor is placed in the pocket (the materialproperties of the pocket would need to be used when calculating force).In yet other aspects, a sensor is constructed into the webbing directly.In still other aspects, the connection element or other element bearingone or more sensor elements (of any type) is a layered material or acomposite material and the sensor(s) are disposed internally betweenlayers of the layered or composite material.

In accord with some embodiments of the present concepts, sensors whichmeasure linear displacement can be used in the system. Preferably, thesensor can be capable of measuring strains in the range of about 0.05-5%for current webbing. Traditional strain sensors with a medium strainrange generally include those with a strain range 0%-10%. Other sensorsinclude hyper elastic sensors with a large strain range (e.g., liquidmetal such as disclosed in WO 2013/044226 A2, which is herebyincorporated by reference in its entirety). Alternatively, traditionalstrain sensors with low strain range can be used by making the areawhere strain sensor is attached very stiff to lower the webbing strain.

FIGS. 41A-41B shows alternative embodiments of the present conceptswherein actuators 200 apply forces to both sides of the hip joint (FIG.41A) or to the ankle (FIG. 41B). The actuators could be any device thatcauses the two ends of the blocks, shown at the front and rear of thethigh in FIG. 41A, to move together. The actuators could include, forexample, a Bowden cable connected across the space, a pneumatic actuatorcontrolled by a hose, or by an electromagnetic actuator having adisplaceable plunger.

In accord with some embodiments of the present concepts, actuation canbe provided at the hip joint to assist with motion and, in particular,walking, running and jumping. Also, as the hip joint is close to thetorso, force can be transferred directly from a torso-mounted actuatorto the hip joint itself. This can be accomplished by pulling on the hipwith a tensile element such as a cable, piece of webbing, ribbon, etc.With no sheath required for this tensile element, the friction will bevery low and thus the efficiency of the system high. One benefit of thehip joint being located close to the torso is that donning and doffingthe soft exosuit is readily accomplished. The actuator, located on abackpack or fanny pack structure on top of the user's clothing, and thetensile elements can remain outside the body and secured to the thighwith a brace that is also outside the clothing and thus provide for alow-profile device that is easy to attach to and remove from the thigh.

The soft exosuit 100, in accord with at least some of the presentconcepts, comprises an actuator unit with a length of webbing,strapping, cable, or another other means of applying tensile forces(called the “ribbon” henceforth) extending from it and attaching to thehip. In operation, the actuator unit 120 can retract the ribbon tocreate forces causing the hip to extend, and extend the ribbon causingthe ribbon to slacken.

As discussed herein, the actuator unit 120 can be attached to a personsuch as by a waist belt or a backpack. Other components could be used tosecure the actuator relative to the user (e.g., on the posterior side,anterior side, or distributed about both the posterior and anteriorsides). In accord with some embodiments of the invention, the actuatorcan be attachment by two screws which can be found on both sides of thedevice and which gives the option to attach the unit facing in eitherdirection—the ribbon can either extend from the device close to theperson or with some offset from the person. The device could also bemounted further up on the user's back, with the ribbon running parallelto the back for some distance. In some aspects, the ribbon extendingfrom the actuator unit 120 can wrap or extend around the user's glutealregion to cross the hip. The lower end of the ribbon can attach to abrace around the thigh, which could potentially extend around the kneeand all the way down to the ankle for increased support in someembodiments.

When the actuator unit 120 retracts the ribbon, the ribbon will tend topush into the gluteal region if the hip is flexed due to the change inangle of the ribbon. To prevent discomfort from this configuration,several solutions are possible. One is to have the ribbon offset fromthe body to some extent at the actuator end, such as is shown in theleft, center of the above figure.

This will increase the hip angle that can be reached before the ribbonpushes into the gluteus. Another option is to have a wide ribbon (e.g.,2″), to minimize pressures on the wearer. A low-friction material alsomay be worn on the gluteal region to reduce friction and increasecomfort of the ribbon moving against the body. A sheath may also be usedover a large length of the ribbon, i.e. a Bowden cable could be used, toprotect the body from motion of the ribbon. An alternate means ofreducing pressures on the body is to offset the distal end of the ribbonat the thigh attachment. This could be accomplished with rigid orsemi-rigid components attached to the thigh brace, which may extendbackward as a “spur” to provide an offset for the ribbon connectionpoint from the thigh. For example, in one embodiment of a hip attachmentsystem, a piece of fabric can be secured around the thigh with VELCRO®in the front. The actuator can attach to this thigh brace with a 2″ wideribbon, and the top of this ribbon can be pulled upward. The thigh braceis restricted from moving up the user's leg due to the conical shape ofthe thigh. Also due to the conical shape, there is little to prevent thethigh brace from moving downward, and so it can have a tendency to slipdown the leg if there is no tension on the ribbon pulling it upward. Thethigh brace can be held upward by other elements connected it to a waistbelt, or by other means.

In some aspects, an actuator unit 120 ribbon (webbing, cable, etc.)extends down over the gluteal region of the user and connects directlyor indirectly to a soft element that engages the thigh (e.g., thighbrace). In one aspect, a rigid or semi-rigid spur can be used to createan offset from the back of the thigh. In one example, a semi-rigidelement is connected at the back of the thigh and, as force is appliedvia the ribbon to the bottom of the semi-rigid element, it bendsoutwardly from the thigh, thus increasing the offset (and moment) fromthe thigh. This could be useful for creating a low-profile suit thatcollapses against the body when not in use, and creating a larger momentarm when large forces are needed. At intermediate forces, the moment armcould be in an intermediate position. Many other configurations ofelements, each having different amounts of stiffness can be used in asingle system, including various arrangements of soft, flexible, rigid,and semi-rigid elements. Springs and other elastic elements can also beincluded as elements of the system for regenerative purposes.

In accord with one or more embodiments of the present concepts, theactuator unit 120 comprises a motor driven drive pulley adapted toengage and wind the ribbon in response to control signals from a controlsystem. The drive motor can be connected to the drive pulley using atransmission. The transmission can include a timing belt and timinggears or a set of gears that transfer power from the drive motor to thedrive pulley. In alternative embodiments, a drive shaft and one or moregears or timing pulleys can also be used to connect the drive motor tothe drive pulley to wind and unwind the ribbon at a predefined rate toprovide motion assistance. The actuator can also include an idler pulleythat engages the ribbon and measures the force applied on the idler. Theforce signal, for example, provided by one or more strain gauges, can betransmitted to an actuator controller to control actuation of theribbon. Additional sensors can be provided on the hip or other joints ofthe user to detect motion and control the actuator to provideassistance. For example, flexion of hip can be an indication that theuser is starting to move.

In accord with some embodiments of the present concepts, a controlsystem can be provided for one or both legs to control the actuator andreceive signals from sensor to detect motion and adjust the actuatorforces to coordinate them to the motion, as described above.

In accord with one embodiment of the present concepts, constructed as alightweight, small and quickly-built prototype, shown in FIG. 42A, allsystem components are mounted between and/or on two aluminum side plates400, the alignment of which is realized by dowel pins. The side plates400 comprise cutouts 402 to lighten the entire system and/or provideaccess to specific parts of the system. In the example shown, anactuator 200 uses a pulley 235 adapted to drive a 2″ webbing to transmitforce to the back of a user's thigh to apply a moment about a person'ship; other similarly configured examples could utilize webbing ofdifferent width if desired. The use of a wide ribbon instead of a Bowdencable, shown in prior embodiments and examples, allows the material tocontact the user's body without cutting or incising. However, narrowerwebbing sizes or cables could be advantageously used in combination withreinforced fabric, elements (e.g., padding, Delrin, etc.) or guides tosimilarly reduce the ability of the webbing to chafe, cut or incise.

The hip system will tend to touch the gluteal region especially when aperson does motions like squatting or climbing stairs. The ribbon travelis about 200 mm (8″), which facilitates activities such as squatting. Byusing wide webbing and a spool the ribbon can be wound up for multipleturns of the spool without the need for additional guiding features. Forwinding up a round cable the spool needs to have additional grooves andprobably some kind of feeder to locate the cable within the grooves.Furthermore, Bowden cable losses are higher compared to the lossesexperienced when using a ribbon. The main disadvantage of having widewebbing is that it may fold back on itself since the hip has threedegrees of freedom. To prevent folding, flanges can be attached to thepulley which guides the ribbon.

Initial measurements of the hip speed revealed that linear speeds ofabout 0.325 m/s are needed to actuate the hip at its maximum speedduring walking, jogging, jumping, and squatting. This linear speed isdue to the angular velocity of the hip joint in combination with theoffset of the tensile element around the gluteus muscles, a distance ofaround 8 cm. The system uses a motor gear box with a 23:1 gear ratio anda timing belt with a 3.333:1 transmission ratio. So, the overall gearratio is about 77:1. The spool diameter also has a significant influenceon the ribbon speed and therefore enables the system to be used flexibleconcerning ribbon speeds.

One challenge in designing a compact system is to find the best positionof motor 246, gearbox 244 and encoder 248 that will not unduly restrictmovements of the wearer. The assembly of these parts has a length about150 mm. In some aspects, spur gears or bevel gears can be used to attachthe drive unit in a 90° angle. The timing belt 270 (see FIGS. 42B, 43A)provides a high flexibility with respect to positioning of the driveunit 223 (FIG. 30). The timing belt 270 allows a flexible adaption ofthe system transmission by changing the diameter of the timing pulleyswithout changing the position of the drive unit 223. Using spur gears orbevel gears would set the unit on a fixed position which cannot beeasily changed. In at least some aspects, the timing belt 270 designcomprises two timing pulleys 271, 272 and an idler 273 which appliespretension to the system. The maximum belt force is about 300N, which isconsistent with the allowed force on the gearbox shaft.

As shown in FIG. 42F, the drive shaft 265, an off-the-shelf Misumi part,has a 12 mm diameter on the shorter end (left) and a 10 mm diameter onthe longer end (right), selected to fit the 12 mm minimal inner diameterfor the selected timing pulley 271. In addition, the flange 274 of thepre-tensioning idler 273, shown in FIGS. 42B-42C, should prevent thebelt 270 from slipping down. The large timing pulley 271 comprises anoptional skeletonized structure to advantageously reduce the weight ofthe part. As shown in FIG. 42E, the pre-tensioner consists of a shaftand two bearing that are secured by a retaining ring.

As shown in the example of FIG. 43B, several idlers 232 and 275-276 areused to guide the wide webbing used in some aspects of the presentconcepts. To measure forces within the system two load cells 234 areused. When force is applied to the ribbon the two load cells 234 arepulled in a direction which causes a capacity change in the load cellsproportional to the applied forces. In order to assure that the ribbonalways has the same angle along the force measuring idler 232 one ormore additional idlers (e.g., 275-276) are used. In some aspects, theangle to measure forces is about 13°. As depicted in FIG. 43B, themechanism controls movement of the ribbon (not shown) and also keeps theangle to the force sensor constant.

The actuator described here could be implemented a number of differentways. It could include a ratcheting spool and clutch, to permit thespool to retract freely but resist extension except when unlocked by theclutch. This could provide a very low-power solution, in which theactuator merely resists further extension and any forces applied to thebody are those stored from previous motion of the body. This mechanismcould also include a spring in series with the ribbon to permit energystorage and energy return.

Alternately, the actuator could include a mechanism powered by atensioning spring that acts to continuously retract the webbing with alight force. In conjunction with a back-drivable actuator or ratchetingmechanism, this could permit the ribbon to track the motion of the hipcontinuously without needing to use the actuator. Then, the actuatorcould apply forces to the ribbon when needed.

A ratcheting mechanism could be used to connect the spool to the motorbecause the motor only applies forces that pull in one direction on theribbon. This could be used in combination with a light tensioning springthat was winding up the spool. If the motor turned in one direction, itcould engage the ratchet mechanism and transfer torques to the spool. Ifthe hip was moved in extension so fast that the actuator could not keepup with the motion, the ratchet mechanism would permit the spool to movefaster than the motor and continue winding up the ribbon. If the hip wasflexed, then the motor could rotate a small distance to disengage theratchet, at which point the hip would be free to move without the motorresisting its motion. Alternately, a small clutch mechanism could beused to engage or disengage the motor from the spool.

FIGS. 44A-44C show, respectively, front, back and side views of a softexosuit (V3.2) in accord with at least some aspects of the presentconcepts. Connection element 1 connects the two sides of the waist belttogether, which secures the anchor points and keeps the soft exosuitfrom sagging when downward forces are applied to it. Connection element2 maintains tension between the waist belt and thigh brace. Its locationat the side of the thigh allows it to maintain a constant tensionthroughout the stance phase. Connection element 3 constrains node 1 inthe downward and medial direction. Connection element 4 acts to balancethe forces at the thigh brace by counteracting tension from Connectionelement 7 and, further, allows the suit to be pre-tensioned by putting avertical force on the thigh brace. Connection element 5 also constrainsnode 1 in the downward vertical and lateral directions. Connectionelement 6 was added to increase the tension across the front of thethigh. Connection element 7 applies an upward force on the inside of thethigh brace in order to even out the upward forces applied to the thighbrace. Calf connection elements 8-9 are attached in front of the knee sothat the tension created during actuation creates beneficial momentsaround the knee.

FIGS. 45A-45D show, respectively, front, back and side views of a softexosuit (V4) in accord with at least some aspects of the presentconcepts. In relation to FIGS. 44A-44C, connection elements 4 and 6 wereadded to constrain node 2 in the downward vertical and lateraldirections, connection elements 8-9 were added to replace the connectionelements on the front of the thigh (to allow for better forcedistribution that reduced the amount of rotation of the thigh brace),and connection element 10 was added to increase the adjustability of thecalf strap placement. Connection element 12 is attached to the bottom ofconnection element 10 at a slight angle. Connection element 10 is thenaligned and fastened between the thigh brace layers so that connectionelement 12 is placed correctly with respect to the center of rotation ofthe knee. The geometry of connection elements 4 and 6 were found tocreate a very high stiffness path between node 2 and the pelvis,resulting in node 2 deflecting very little under high loads. Connectionelements 8-9 were also found to distribute the load effectively andevenly between node 2 and the thigh brace, eliminating thigh bracerotation.

FIGS. 46A-46B shows front view and rear view pictures, respectively, ofan example of a soft exosuit worn by a user in accord with at least someaspects of the present concepts.

FIG. 47 presents a comparison of statistics showing evolution of initialembodiments of soft exosuits in accord with at least some aspects of thepresent concepts. In the first version (V1) of the soft exosuit 100, themaximum walking speed was 1.25 m/s (2.8 mph), with a total power draw of59.2 W, a battery duration of 4.1 hours (2.5 kg of batteries), a maximumoutput force of 150 N, and a stiffness at 100 N of 3500 N/m. In thesecond version (V2) of the soft exosuit, the maximum walking speed was1.5 m/s (3.4 mph), with a total power draw of 59.2W, a battery durationof 4.1 hours (2.5 kg of batteries), a maximum output force of 200 N, anda stiffness at 100N of 4000 N/m. In the third version (V3) of the softexosuit, the maximum walking speed was 2.0 m/s (4.5 mph), with a totalpower draw of 50 W, a battery duration of 5.5 hours (2.5 kg ofbatteries), a maximum output force of 270 N, and a stiffness at 100 N of5000 N/m. These improvements in performance were also accompanied by adecrease in the overall weight of the soft exosuit 100 (exosuit,actuators, electronics, batteries, etc.), as is shown in FIGS. 48A-48B,which show a bar chart depicting a decrease in weight of soft exosuitsfrom soft exosuit V1 (12.2 kg), to soft exosuit V2 (10.00 kg), and tosoft exosuit V3 (6.53 kg).

FIGS. 49A-49E show kinematic results for the soft exosuit 100 shown inFIGS. 46A-46B. FIG. 49A shows right ankle angle as a function ofpercentage of gait cycle (upper left), FIG. 49B shows right knee angleas a function of percentage of gait cycle (upper right), and FIG. 49Cshows right hip angle as a function of percentage of gait cycle (lowerleft). In each of these graphs, a first plot 301 shows the respectivekinematic angles when the soft exosuit 100 is in a “slack” non-actuatedcondition during movement and a second plot 302 shows the respectivekinematic angles when the soft exosuit 100 is actuated during movementat a level of a 150 N assisting force applied to a footwear connectionelement 130. Significantly, the close correspondence in the kinematicangles for each of the joints as between the slack condition and theactuated condition demonstrates that the operation of the soft exosuit100 does not markedly or negatively impact gait. Likewise, FIG. 50 showsa force versus time curve for ankle actuation performance for the softexosuit 100 shown in FIGS. 46A-46B. The data was recorded while thesubject was walking at 1.25 m/s, with a local peak force of up to 300 Nrepresented in graph 302 (actuated), as compared to the forces when thesoft exosuit 100 is in a “slack” non-actuated condition during movement(graph 301). Again, graphs 301, 302 in FIG. 50 show a closecorrespondence as between the slack condition and the actuated conditionof the soft exosuit 100.

FIG. 51 shows metabolic results for different subjects, under similartest conditions, utilizing the soft exosuit 100 shown in FIGS. 46A-46Band represented in FIGS. 49-50. For subject 1, subject 1 expended 710 Wof energy during movement while wearing the soft exosuit 100 in a“slack” non-actuated condition, but expended only 611 W of energy duringsimilar movement while wearing the soft exosuit 100 and wherein theankle was activated during movement, for a reduction of expended energyof 99 W (a 14% reduction in expended energy). Subject 2 expended 530 Wof energy during movement while wearing the soft exosuit 100 in a“slack” non-actuated condition, but expended only 460 W of energy duringsimilar movement while wearing the soft exosuit 100 and wherein theankle was activated during movement, for a reduction of expended energyof 70 W (a 13% reduction in expended energy). Similar, but lesser,benefits were realized by subjects 3-5. Based on this sample, theaverage reduction of expended energy was 53 W, a 9% reduction inexpended energy.

FIG. 52A shows a biological metabolic power pie chart indicating that, atotal joint active power at a walking speed of 1.25 m/s comprises a 46%contribution from the ankle, a 40% contribution from the hip, and a 14%contribution from the knee. The soft exosuit 100 metabolic benefit, intesting thus far, has shown a metabolic benefit (reduction in expendedenergy) of up to 12% at the hip and 14% at the ankle, as shown in FIG.52B.

FIG. 53 shows evolution of soft exosuit 100 stiffness between differentversions of soft exosuits (v3-v7) in accord with various aspects of thepresent concepts. The subject wore a number of different versions ofsoft exosuit 100 including V3, V3.1, V3.2 (see FIGS. 44A-44C), V5 (see,e.g., FIGS. 14A-14B, FIGS. 46A-46B) and V7 (see FIGS. 54A-54E ₃).Through the evolution of the disclosed soft exosuit 100 from V3 to V7,the resultant stiffness of the soft exosuit 100 increased markedly andnonlinearly.

FIG. 54A-54E ₃ shows aspects of a soft exosuit (V7) in accord with atleast some aspects of the present concepts. In each of FIG. 54A-54 ₃,the following reference numbers are used: (1) connection elements, suchas webbing or strapping material; (2) an inextensible fabric; (3) 1″webbing connected to top of waist portion of the suit for securingaround the wearer's waist; (4) routing pockets for cable and calf strapwebbing; (5) cable (e.g., Bowden cable); (6) spandex base material; and(7) slideable part of Bowden cable connection to the soft exosuit.Overall, the soft exosuit 100 of FIGS. 54A-54E ₃ comprises two leggingportions 400 and a waist attachment 3 that encircles the waist. Thewaist attachment 3 is similar to the waist belts 110 describedpreviously (see, e.g., FIG. 13) in that it is adjustable (e.g., at theback, side or front) and has webbing strengthening the fabric in higherstress areas.

In one aspect, a first piece of webbing for the waist attachment extendsfrom the top of the iliac crest on each side of the leg and crosses overto the opposite leg and a second piece of webbing extends around the hipon the same side. A 1″ belt is provided in or the waist attachment 3(optionally secured by sewing, straps, loops, snaps or other means ofsecurement), allowing the suit to be secured around the waist (e.g.,loosely secured while the rest of the soft exosuit is tightened, snuglysecured during use, etc.). In one embodiment, a fly-type opening isprovided on the front of the suit (e.g., in the center or offset fromthe center), where the two sides can be readily, but securely connected(e.g., via Velcro®, zipper, buttons, etc.) or separated. A Velcro®-basedfly-type opening permits the soft exosuit 100 to be better adapted tofit a variety of physiologies. The entire waist portion is constructedof a largely inextensible fabric, strengthened with Velcro®. Foaminserts are desirably positioned over the iliac crest regions of thepelvis to provide additional padding for comfort.

The waist attachment 3 connects to the legging portions 400 through alarge patch of VELCRO®, as shown in FIG. 54C ₄, which can be compared toFIG. 54C ₄, wherein the same section of the left leg 2 is connected bythe large patch 2 of VELCRO®. This patch of VELCRO® is on top of a largepatch of inextensible fabric 2 on the front of the thigh. The rest ofthe legging portions are constructed of a stretchy spandex material 6.This construction prevents the front of the thigh from stretching whenloads are applied to the suit. The wide fabric area distributes loadsacross the thigh, minimizing displacement and pressure. This wide fabricarea is held closely against the thigh with the spandex around the backof the suit. The spandex should be stretched and pull the inextensiblefabric tightly against the thigh to prevent it moving during softexosuit operation.

Also attached to the VELCRO® on the front of the thigh are twoconnection elements (e.g., straps) that extend from the front of thethigh through the knee and to the back of the calf (similar toconnection elements 107 shown in FIGS. 14A-14B). A bottom portion ofthese connection elements are shown as reference numeral 1 FIGS. 54E₁-54E₃. These connection elements pass through spandex pockets on thesides of the soft exosuit, which extend from just above the knee to thebase of the calf. The spandex at the base of the pocket between theconnection elements and the skin helps prevent chafing and rubbing fromthe connection elements on the skin. The spandex on the top of thepocket enclosing the connection elements is to keep the connectionelements lying flat against the leg, which can increase stiffness, andprevent the connection elements from being a snag hazard. The VELCRO®attachment at the front of the thigh permits the effective length of theconnection element to be changed so the suit is adjustable for differentheights of wearer, as well as tensioning the suit to the appropriatelevel. This adjustment could be accomplished by strapping and buckles,lacing, or any other means.

In another configuration, instead of having the connection elements 1 ofFIGS. 54A-54E ₃ slide within a pocket, they could be sewn into thegarment to make inextensible portions of the fabric. Thus in general,the soft exosuit 100 would comprise a spandex under-layer with regionsof inextensible fabric sewn in to create paths where the soft exosuitwould not stretch and would transfer force. Alternatively, the softexosuit could comprise a spandex fabric with regions reinforced withinextensible fibers woven into the fabric.

In general, the leggings 400 could be combined into a single pantstructure, which would consist of the two leggings sewn together into atraditional pants shape by adding spandex at the top, which would coverthe wearer's posterior and groin region. This pant structure would gounder the waist attachment structure.

On top of or adjacent to the pocket that contains the connectionelements 1 going to the back of the calf, a second pocket is sewn whichcontains the Bowden cable going down to the back of the calf, as shownin FIGS. 54E ₁-54E₃.

A connection element utilized in the spandex pocket may comprise, forexample, a webbing strap that is 2″ wide at the top and bottom, in orderto provide a large surface area against the calf and to minimize strain,and 1″ wide in a mid-section, which corresponds to a location of theknee. This configuration is presently accomplished by sewing togetherdifferent widths of webbing, but such structure could alternatively beachieved by creating a custom-woven piece of webbing. The webbing tapersto 1″ wide around the knee to prevent the webbing from bulging outward alarge amount when the knee is bent, such as occurs during the swingphase of walking. If the strap were 2″ wide all the way down, thewebbing would bulge out more than 1 cm at times which can rub againstthe opposite leg during walking.

As shown in FIGS. 54E ₁-54E₃, the Bowden cable 5 attaches to theconnection elements 1 extending down the side of the leg through asliding attachment. The connection elements loop through a metal slide(webbing buckle) after going down one side of the leg and beforeextending back up the leg. This permits the length of the connectionelements on the right side and left side to equalize when forces areapplied to the cable. With this sliding mechanism, the Bowden cable 5will move along the connection elements 1 until it reaches the positionof least energy, which will tend to be in the center of the calf, sincethe end of the inner cable 5 is secured at the back of the heel.

FIGS. 55A-55B show aspects of a soft exosuit 100 in accord with at leastsome aspects of the present concepts. The soft exosuit 100 of FIGS.55A-55B provides appropriate assistance to hip flexion and extension byusing Bowden cable actuation to create a parallel force to accompany hipflexion and extension and is similar in concept to the embodiment shownin FIG. 41A. In this aspect of the present concepts, the soft exosuitcomprises a waist belt (1), thigh braces (2) which hold the distal endof anchor points for Bowden cable, and connection elements (e.g.,webbing straps) (3), which form the proximal end of anchor points forBowden cable, and two stretchable side connection elements (e.g.,webbing straps) (4) on the side of the legs for holding the positions ofthigh braces from dropping. The anchor points on the front side of theleg for hip flexion are labeled as points 5 and 7 in FIGS. 55A-55B andthe anchor points for hip extension are labeled as points 6 and 8 on theback side of the leg. The proximal anchor points 5, 6, for hip flexionand extension, respectively, are right above the hip joint, while thedistal anchor points 7, 8 are on the top side of the thigh braces 2,which are also in the same sagittal plane with 5 and 6, respectively.

Each of FIG. 55A and FIG. 55B also show, adjacent thereto, detailfigures showing the Bowden cable 142 and load cell 425 attachments. TheBowden cable sheath 144 is connected to the proximal end anchor points5, 6, and the inner cable 142 with the load cell 425 in between isattached to the distal end anchor points 7, 8 on the thigh brace 120. Toassist the hip joint, the soft exosuit 100 creates a contracting forceby actuating the Bowden cable 142 to bring those anchor points 5-8closer to each other, thus creating an upward parallel force with thehip flexor and extensors, respectively. Because the anchor points areseveral centimeters away from the hip rotation center, the contractionof the Bowden cable 142 creates hip flexion and extension torques. Byimplementing the actuation of the Bowden cable 142 at the right timing,torque created by the soft exosuit synchronize with the hip muscles tohelp with wearer's propulsion and swing during walking (or running),thus decreasing the wearer's energy expenditure and improving metabolicpower.

The thigh brace 2 shown in FIGS. 55A-55B comprises, in at least someaspects, a low-stretch cotton or other low-stretch material that wrapsaround the thigh and is secured with Velcro®. Four low-stretch polyesterwebbings are warped outside the low-stretch cotton to form the twodistal anchor points for the Bowden cable 142 and distribute the tensionforce around the thigh brace 2 when the suit is actuated. Sewn into, orotherwise integrated with, the low-stretch cotton are four straps of 2″polyester webbing. When assisting with hip extension, these two strapsoriginate in the top of the posterior of the thigh strap, wrapdiagonally around to the anterior where the two cross, and then wrapback to the posterior where they are secured on top of one another usingVelcro®. Stretchable side webbing straps 4 are 1″ wide, 18″ longstretchable cotton with Velcro® on both ends and connect the waist belt1 and the thigh brace 2 in order to keep the thigh brace in positionwhen the suit is not actuated.

FIGS. 56A-56B show aspects of a waist belt 110 for a soft exosuit inaccord with at least some aspects of the present concepts. The waistbelt 110 comprises, in the example shown, a back pad 9, two side pads10, and two diagonal connection elements (e.g., straps, webbing) 11. Thewaist belt 110 was designed to distribute the force from the BowdenCables 142 (not shown in FIGS. 56A-56B) through the diagonal straps, tothe iliac crests, and around the waist. When the Bowden cable 142 isactuated, the downward force on the waist belt 110 starts at thediagonal connection elements 11 right above the hip joint. Owing to thisconfiguration, the normal force created by the tension on the Bowdencable 142 will not add up extra torque to affect the desired flexion orextension assistance and the downward forces are distributed around the4″ inch wide waist belt 110.

FIG. 57 shows aspects of another waist belt 110 (V5) for a soft exosuitin accord with at least some aspects of the present concepts. In FIG.57, labels show components that transfer force from the right leg to thepelvis. In this version, for each leg, one connection element 5 (e.g.,webbing strap) crosses the front of the pelvis to attach to the oppositeside of the pelvis, and one connection element 2 (e.g., webbing strap)wraps around the side of the pelvis on the same side as the leg.Connection element 5 terminates on the top of the iliac crest of thepelvis. Connection element 2 wraps around the hip below the iliac crest.Both connection elements 2, 5 then connect to a wide waist belt 110which goes behind the person and sits on the small of their back andpelvis in the back (see also reference numerals 9,10,11 in FIG. 58C,which has a similar construction in the back). This configurationpermits high forces to be transferred to the waist because the top ofthe pelvis (where the cross-strap terminates) acts as a ledge whichresists downward and sideways forces (see inset photo). On thesame-side, the hip is stiff which resists the inward forces caused bythe strap wrapping around the side of the hip. The downward force of thestrap is resisted by the small of the back and back of pelvis.

In yet other aspects, another system of connection elements that willdisplace less under the same force can be achieved by the topology shownin FIGS. 58A-58F, which has the same component numbering as FIG. 57.FIGS. 58A-58F shows aspects of yet another waist belt (V5) for a softexosuit and shows a waist belt attachment to apply forces to the rightleg, with FIGS. 58A-58C showing components of the waist belt and FIGS.58D-58F showing how the waist belt is positioned relative to the iliaccrest of the pelvis, which is shown by the arcs drawn on the photos. InFIGS. 58A-58B, in addition to connection elements (e.g., webbing straps)2 and 5, connection element 1 and 4, which form a V-shape, are added, asis connection element 6 which connects connection element 1 and 4 toconnection element 2 and 5. Connection element 1 goes above the iliaccrest on the same side of the pelvis as that which the load is applied(the right side, as shown). Connection element 4 goes above the iliaccrest on the opposite side of the pelvis. The junction of connectionelement 1 and connection element 4 then is connected to the junction ofconnection elements 2 and 5 via connection element 6. In thisconfiguration, connection elements 1 and 4 support some load, butconnection element 1 will slip over the side of the iliac crest underhigh forces. However, in conjunction with connection elements 2 and 5,this can be used to increase the maximum force able to be applied to thepelvis, or can increase the stiffness of the attachment to the body(measured by pulling down on the bottom of connection element 6 andrecording the applied force vs. resulting displacement of that point).

To achieve ideal load-sharing between these connection elements, thetension should be set in connection elements 1, 2, 4, 5 and 6 so theyare all approximately equal. Alternatively, because connection elements2 and 5 take more force than connection elements 1 and 4, the tension inconnection elements 2 and 5 can have higher tension than 1 and 4, orconnection element 6 can be made to have lower tension such thatconnection elements 2 and 5 need to displace slightly to draw taut.

Also in FIG. 58A, the gap between connection elements 1 and 2 is labeledas reference numeral “3”. The bulk of the iliac crest protrudes in thisgap. It is covered by a Spandex stretch material which connectsconnection elements 1 and 2, although this can be left uncovered with nofabric as well. The material is resilient (e.g., permitting connectionelements 1 and 2 to move relative to each other in the verticaldirection) so that downward motion of connection element 2 does not pullconnection element 1 over the edge of the iliac crest. FIG. 58B alsoshows a waist belt 7 connected in the front by a buckle 8. The waistbelt 7 is useful for pulling the connection elements snugly against theiliac crest, and holding the entire structure up while the connectionelements are tightened.

In general, fabric that stretches less than about 20%, ideally withstretch less than about 5%, can be used in place of any of theconnection elements in these and other figures.

FIGS. 59A-59D shows aspects of yet another waist belt 110 (V7.1) for asoft exosuit in accord with at least some aspects of the presentconcepts. FIG. 59 shows a waist belt attachment utilizing fabric as acompliant element to balance forces within the waist belt, with the toprow showing components of the waist belt and the bottom row showing howthe waist belt is positioned relative to the iliac crest of the pelvis,which is shown by the arcs drawn on the photos. In the example of FIGS.59A-59D, the reference numerals used refer broadly to the samecomponents as in FIGS. 57-58F. Here, connection elements 2 and 5 aresimilar to the connection elements in the FIGS. 57-58F, connecting abovethe iliac crest on the opposite side of the body and below the iliaccrest on the same side of the body as that which forces are applieddownward to the waist belt. Now, connection elements 1, 4, and 6 havebeen replaced by a fabric, which covers the front of the pelvis withmore surface area than the webbing did in FIGS. 58A-58B. Also, thefabric is more extensible than the connection element material.

In this example of FIGS. 59A-59D, the fabric stretched 5% under a loadof 300 N when loaded parallel to the fibers, and the connection elementmaterial (2″ wide seatbelt webbing) stretched 0.2% under a load of 300N. So, when loads are applied downward to the bottom of element 6, theconnection elements 2 and 5 will displace less for a given load than thefabric 1 and 4. This means that the force supported by elements 1 and 4will be less than the force supported by the connection elements 2 and5, due to their relative higher compliance. This permits the suit to beadjusted easily, so it lies flat on the wearer's front when they arestanding vertically, and the forces will be distributed between the twosections automatically. In general, the construction of the waist beltcould be comprised entirely of the same type of fabric, at the cost ofbeing harder to adjust properly for a snug fit.

Element 3 of FIG. 59A comprises a spandex fabric. There is no waist beltin this embodiment because the fabric adequately covers the top part ofthe abdomen and secures the waist belt to the pelvis. A waist belt couldoptionally be added. In general, additional elements could be used, inaddition to the elements (connection elements and fabric) shown in FIGS.59A-59D. It would be possible to place connection elements or fabric toconnect to below the iliac crest on the opposite side of the pelvis. Forexample, after connection element 5 crosses the midline of the person,it could split like a “Y” into two segments, one of which goes over theiliac crest and one of which goes below it.

In the example of FIGS. 59A-59D, the waist belt is constructed so thatthe waist belt principles can be maintained for each leg separately.This permits high stiffness, since fasteners connecting two pieces offabric will likely introduce compliance or hysteresis. It is to be notedthat, in any of the aspects of the soft exosuit disclosed herein, thesoft exosuit may be advantageously configured to have hysteresis. Thismay be useful, for example, because the actuator 200 can move to applyforces when pulling on the suit (e.g. during 40-50% of the gait cycle),which may require fast motions, and then can move more slowly to go backto the original position later (e.g. during 60-80% of the gait cycle).

As to donning of the waist belt of FIGS. 59A-59D, FIGS. 61A-61D isillustrative. The left two images in FIG. 61 are the part of the softexosuit that sits over the right thigh, and the right two images are thepart of the soft exosuit that sits over the left thigh. In each case theimages show the side of the suit that faces away from the person whenthey are wearing it. To don the soft exosuit, first the part of the suitwhich supports downward forces over the right thigh is connected. Aconnection element 2 is placed through a slide (webbing buckle) at theend of connection element 4, which extends from the left side of thebody over the left iliac crest. Connection element 2 is then securedback on itself with VELCRO®. Next, the part of the soft exosuit whichsupports forces on the left leg is connected. Connection element 3 isplaced through the slide on the end of connection element 1, whichextends from the right side of the body over the right iliac crest.Connection element 3 is then doubled back on itself and secured withVELCRO®. In this manner, the waist belt structures which support theright leg are underneath the waist belt structures which support theleft leg, and they are not connected to each other in the middle(although they could be to further secure the waist attachment).Following the attachment of the device around the waist, it is furthertensioned using connection element 7 and VELCRO® 8 on the left side ofthe body, and a similar strap and VELCRO® attachment on the right sideof the body. Connection element 7 in FIGS. 61A-61D corresponds toconnection element 2 in FIGS. 59A-59D.

FIG. 60 shows aspects of the waist belt (V7.1) of FIGS. 59A-59D andshows the grain directions of the fabric. The directions shown by thedouble-headed arrows are the directions in which those pieces of fabricare relatively inextensible. Seams connect these pieces of fabric toprovide force transfer through the desired path. This alignment of graindirections has been determined to provide the highest stiffness. Ingeneral, woven fabrics have warp and weft directions, which are theprincipal axes when the fabric is mounted on the loom. Woven fabricstend to be relatively inextensible along these axes, and relativelyextensible along a set of axes rotated 45° from the warp and weft axes.As such, to create high stiffness in the waist belt fabric, the fabricis sewn as shown, wherein three pieces of fabric are oriented indifferent directions so their axes of lowest stretch (indicated by thearrows) are oriented in line with the force paths the fabric pieces willsustain. Seams can optionally be taped to provide additional lines oflow-stretch material.

FIG. 62 depicts aspects of a soft exosuit in accord with at least someaspects of the present concepts configured for actuation of multiplejoints. In the left image, an actuator 200 is shown having a pulley 224configured to actuate multiple sets of Bowden cables 142 to separateprovide assistive forces to different joints (e.g., ankle, hip). In theright image, the soft exosuit is shown to integrate sensors 350 formeasuring joint kinematics. Exemplary sensors are disclosed in WO2013/044226 A2, WO 2012/103073 A2, WO 2012/050938 A2, and U.S. Pat. No.8,316,719 B2, each of which is hereby incorporated by reference in theirentirety. Further, any of the aspects of the present concepts mayfurther integrate other actively controlled materials such as, but notlimited to, those disclosed in WO 2011/008934 A2 or WO 2013/033669 A2,each of which is hereby incorporated by reference in their entirety. Byway of example, soft exosuits in accord with any of the disclosedaspects may comprise hyperelastic strain sensors located, by way ofexample, at any one or more of the ankle, knee and hip (i.e., attachedto both sides of each respective joint), to measure human biologicaljoint rotations in the saggital plane. The resulting soft exosuit isvery lightweight, cost-effective and easy to don and doff.

FIGS. 63A-63B show examples of a soft exosuit in accord with at leastsome aspects of the present concepts configured for actuation ofmultiple joints. This soft exosuit is formed from a combination ofelastic and inextensible fabrics or material capable of applying forcesacross joints in the lower limbs. Forces in the illustrated example arecreated by contracting a cable with a first end fixed to the suit abovethe joint and a second end fixed below the joint. As described herein,the contracting cable (e.g., a Bowden cable) would transmit forcesthrough the soft exosuit's inextensible members to the various anchorpoints to carry the loading. So configured, the soft exosuit allows formultiple joints to be acted upon simultaneously in a beneficial wayusing a multi-pulley and a drive box, described below. Advantageously,the soft exosuit comprises a sensor system which can measure joint angleof the one or more joints and, desirably, three joints (hip, knee,ankle). The sensors can include, but are not limited to, the sensorsnoted above in relation to FIG. 62 and include any sensor(s) or the sametype, or of different types, that can measure joint angle.

Although the examples of FIGS. 62 and 63A-63B relates to the legs,wherein the activity of interest is walking or running, the presentconcepts include motions other than walking or running, and limbs otherthan the legs (e.g., the arms). Correspondingly, a multi-pulley and adrive box could also (i.e., in addition to the above), or alternatively(separately from the above), provide assistance for arm movements.

FIG. 64A-64B show an example of a multi-pulley for a soft exosuit 100configured for actuation of multiple joints in accord with at least someaspects of the present concepts. Continuing with the example of FIGS. 62and 63A-63B, a multi joint actuation capability is provided by a singledrive unit configured to activate 1-N pulleys (where N is an integer).The drive unit comprises a single input (e.g., shaft) adapted to drive,directly or indirectly (e.g., through one or more gears), a plurality ofpulleys. For joints such as hip flexion and ankle flexion, which operatein tandem, the two pulleys could be active at the same time. Activatingtwo or more pulleys could be done via a permanent connection between thepulleys or a selector which would engage one or more pulleyssimultaneously. Pulleys for each actuation point can have differentdiameters. The ratio of the pulley diameters will allow a single inputto drive actuators at each joint which may have different force andvelocity requirements.

FIG. 65 shows a rear view of a thigh brace for a soft exosuit in accordwith at least some aspects of the present concepts. The depicted thighbrace, shown in an optional single-piece construction, is configured tonot only accommodate varying thigh sizes and provide adjustment pointsabove the knee to allow for a tight fit, but is also configured to allowadjustment for optimal conical form match. Lateral cutouts and aminimized height at the back of the thigh facilitate movement andcomfort, while providing ample securement through Velcro® provided atthe tapered ends. Circumferential adjustment is a simple matter ofreleasing the Velcro® attachment, tensioning the thigh brace as desiredwhile holding one end of the thigh brace stationary, and securing theVelcro® attachment.

FIG. 66 shows Bowden cable termination points for a soft exosuit 100 inaccord with at least some aspects of the present concepts. As previouslynoted, Bowden cable actuators act by reducing the distance between twofixed points. The fixed points operated on herein are points areattachments to the suit and through the suit forces are grounded to thebody above and below the joint(s) acted upon. These grounded forcescreate moments about the joints. A hip flexion moment is created bygrounding the sleeve upper portion of the Bowden cable (1) to the suitabove the iliac crest anterior to the frontal plane and the cable (2)below the iliac crest. The soft exosuit grounds the force created whencontraction of this cable occurs through inextensible fabric around theconical section of the thigh and the waist belt. A hip extension momentis created by grounding the sleeve upper portion of the Bowden cable (3)to the soft exosuit above the iliac crest posterior to the frontal planeand the cable (4) below the iliac crest. The soft exosuit grounds theforce created when contraction of this cable occurs through inextensiblefabric around the conical section of the thigh and the waist belt. Anankle extension moment is created by grounding the sleeve upper portionof the Bowden cable (5) to a point on the calf above the wearers bootand the cable (6) below the wearer's heel. The soft exosuit grounds theforce created when contraction of this cable occurs through inextensiblefabric at waist belt.

FIGS. 67A-67D show aspects of an actuator 200 for a soft exosuit inaccord with at least some aspects of the present concepts. As shown byway of example, such as in FIGS. 46A-46B and FIG. 62, backpack bornactuators are one advantageous implementation of a soft exosuitactuation system. However, due to the size and weight current actuationsystems, it could be awkward to doff were the wearer to need to quicklydrop the backpack and move away from it. Where the Bowden cables arefixed to the power and drive unit, as well as electrical connections,this can present an impediment to such maneuvers. Accordingly, in atleast some aspects of the present concepts, the actuator 200 maycomprise a quick release feature to permit rapid removal of a portion ofthe system that tethers the actuation system to the soft exosuit. By wayof example, as shown in FIGS. 67A-67D, a quick release is configured topermit rapid detachment of a small pulley cassette 510 from the primarydrive 500 (and power boxes). The pulley cassette 510 consists of apulley with Bowden cable mating features as well as a soft exosuitelectrical connection. Accordingly, when the wearer wishes to eject fromthe backpack, he or she simply pulls a cord or pin/skewer attached tothe two securing latches and the latches open, allowing the cassette toeject of the drive spline. Other conventional quick release mechanisms(QRMs) could also be employed to releasably connect the pulley cassette510 from the primary drive 500.

In accord with the example of FIGS. 67A-67D, the ready detachability ofthe disclosed cassette pulley 510 is facilitated by utilization of aspline drive on the motor unit 500 which mates with the corresponding,mating features on the cassette pulley. Large, slim bearing(s) furtherfacilitate utilization of a central spline engagement between the motorof the drive box 500 and cassette pulley 510. Clips retaining thecassette pulley 510 to the motor of the drive box 500 may comprise anyconventional clip that, when opened, allow the unit to be freed. Springclips are presently preferred, but are not required. In addition, keyingpins or features and/or alignment features which resist motor torqueallow motor power to be transferred to the pulley when the units areconnected.

Use of contact spring pins (e.g., POGO pins) allow establishment of astable electrical connection between the cassette pulley 510 and thedrive box 500 that permits two-way signal and/or two-way powertransmission (e.g., regenerative power transmission) between the softexosuit 100 and the drive box 500 without a permanent connection. Whenthe cassette pulley 510 is ejected, the electrical connections aretemporarily severed. A similar system of quick connects can beimplemented for any soft exosuit that utilizes fluidic or airconnections for any on-board soft exosuit system (e.g., actuation,etc.). Once the cassette pulley 510 is ejected, nothing connects thewearer of the soft exosuit to the backpack (or fannypack) bearing theactuator 200 and/or associated systems, and the backpack may be quicklyremoved without impediment. The cassette pulley 510 may be held in hand,dropped to hang free, or may be quickly inserted into a pouch or pocketin the wearer's clothing (e.g., if the soft exosuit is worn underclothing) or a pouch or pocket of the soft exosuit, if provided andaccessible.

Another optional, but advantageous, feature of the actuator 200 of FIGS.67A-67B comprises an integrated fast-swappable battery system. Thispermits rapid removal of a depleted or insufficiently charged batteryand replacement of a new battery and/or replacement of an existingbattery for a larger or smaller battery to change the operationalenvelope of the soft exosuit (e.g., to increase a battery duration, todecrease a system weight where a lower capacity and lighter batterysatisfied mission specific or task specific goals, etc.). FIGS. 67C-67Dshow the battery box removed from and beneath the drive box 500 andfurther show the cassette pulley 510 ejected from the drive box.

As shown, the drive box 500 comprises a passive cooling system (i.e.,air cooled). Although, in some aspects, cooling fans are suitably usedto maintain the motor within an appropriate temperature operating range,some tasks and operational conditions benefit from an air cooled coolingsystem. In such aspects, the motors are cooled by a radiant fin system(e.g., a machined aluminum block comprising a conductive base having aplurality of fins projecting outwardly therefrom) placed over a surfaceof the motor (e.g., a top half of the motor) to permit conductive heattransfer from the motor to the conductive base and fins of the radiantfin system, which the convectively transfers heat from the fins to theatmosphere). This fins system has the benefit of silent cooling andallows for a sealed device. The air cooled system advantageously issilent, reduces the overall power requirement of the actuator system,and avoids openings in the actuator system from which waste heat wouldotherwise be discharged by the (omitted) cooling fan.

FIGS. 68-70 show various aspects of control schemes that may beimplemented for a soft exosuit in accord with at least some aspects ofthe present concepts. Such control schemes are flexible and can beadapted as desired for a particular suit and application. By way ofexample, the soft exosuit 100 of FIG. 68 comprises a plurality ofhyperelastic strain-sensors (such as disclosed in WO 2013/044226 A2) tomeasure suit stiffness and pressure. By way of example, suchhyperelastic strain-sensors may comprise a stretchable silicone rubber(e.g., EcoFlex 0030, SmoothOn; PDMS, Dow Corning) sheet embedded withconductive liquid microchannels of non-toxic eutectic gallium-indium(eGaIn), wherein deformation of the channels causes a change inelectrical resistance corresponding to the change in length (which inturn can be related to the rotation of the joint). As shown,hyperelastic strain-sensors are disposed across the ankle, knee and hipto measure changes in angle of the monitored joints. The hyperelasticstrain sensors can be disposed in parallel with the force-path of theactive suit in order to measure real-time suit deformations, such asshown in FIG. 68.

The control system is able to relate, via a human motion patterndetection algorithm or look-up table, the sensed movements of the joints(e.g., looking only at absolute changes in angle, looking at changes inangle in relation to time, velocity and/or acceleration, etc.) to one ofa plurality of predicated activities such as walking on a level surface,walking on an incline, walking on a decline, running on a level surface,running on an incline, running on a decline, walking up stairs, walkingdown stairs, crouching, crawling, jumping, limping, favoring one limbover the other, etcetera. Based on this motion data, the control systemmay (1) store the data on a local physical storage media, (2) wirelesslytransmit the data to another local or remote device via an on-boardcommunication system, (3) transmit the data, through a wired connection(e.g., communication cable), to another local or remote device, devicevia an on-board communication system and/or (4) use the data to providereal-time force assistance control to adapt the suit seamlessly to thewearer's state of activity and environment. For example, if the softexosuit measured joint deformations are above a threshold defined basedon comfort (e.g., user preference) and/or suit mechanical capabilitiesconsiderations, the control system may be configured to automaticallydecrease assistance level until these deformations are again within adesired operational region. Additionally, the soft exosuit may be usedin combination with an active, wearable exoskeleton. In suchimplementations, the measurement data can be transmitted wirelessly orthrough a wired connection to a controller of the exoskeleton to therebycause the exoskeleton to adapt the level of assistance. Moreover, thesoft, hyperelastic sensors can be used to measure pressure in relationto any point of interface between the wearer and the soft exosuit, whichcan be used for online adaptation of the assistance level based oncomfort considerations.

Additional control schemes can be used with the soft exosuit if a forcesensor is used to measure tension in the cable (e.g., an in-linesensor). The soft exosuit creates tension passively due to thebiomechanics of walking. For a given leg, this tension occurs startingaround 15-35% of the gait cycle, depending on how the soft exosuit isadjusted, and rises as the leg pushes off from the ground. This risingforce can be used as an input to the control system, giving informationabout when and/or how (e.g., force profile, force timing, etc.) the softexosuit should be actuated.

One control scheme from this information involves, first, tensioning thesuit to the point where, during level-ground walking, the peak forcesare at a certain threshold magnitude (e.g., F_(peak)). Once the suit ispre-tensioned in this manner, the force on the cable is monitored andcan be used to predict where in a gait cycle the user is, or is about tobe, since the force on the cable predictably crosses the threshold atthe same point of the gait cycle. With respect thereto, FIG. 77 shows agraph depicting the timing of actuation of the soft exosuit 100 during agait cycle and the corresponding suit force under two conditions: whenthe suit is tensioned 800 and when the suit is actuated 810. Thetensioned graph 800 means that the suit has been set to a certainlength, and then the length is held fixed throughout the gait cycle. Theactuated graph 810 means that the tension in the suit is changed bypulling it together with a Bowden cable, or the like, at the ankle. Ingraph 800, the tension in the suit changes throughout the gait cycle dueto the different motions of the joints (as in FIG. 9D). FIG. 78 shows,for the actuated case 810, the relative timing of the cable position andthe suit force and more particularly a graph depicting the timing ofactuation of the soft exosuit during a gait cycle (as a percentage ofgait cycle) and the corresponding suit force (graph 830) in relation tocable position (graph 820).

In the graph of FIG. 77, the tensioned force crosses 50 N at 40% in thewalking cycle, which is repeatable across many steps. This force occursbefore actuation begins each cycle, and thus this information can begained regardless of if the cable is actuated or not. Thus, for theexample of FIG. 77, where the control system measures a force in theactuating cable that approaches (or optionally equals or exceeds) athreshold force F_(thresh), the control system is able to utilize thisinformation of the wearer's position in the gait cycle to take one ormore actions (e.g., actuate immediately or after a delay). For example,the controller can get an estimate of the person's gait period bylooking at the elapsed time between when the force crosses the thresholdon two successive steps, or on several successive steps and then takingan average.

Further, from this information on the threshold cable force magnitudeand/or flag indicative of crossing a threshold force magnitude, thecontroller also knows where the person is in their gait at that time.For example, the controller could be set to start a position-controlledpull on the cable at 40% in the gait cycle. In this case, whenever thecontroller detected that the force crossed the threshold thatcorresponded to 40% in the gait cycle, the controller could initiate thepull immediately. Or, if the controller was supposed to start aposition-controlled pull at 43% in the gait cycle, then the controllerwould use the gait period to compute the delay between 40% in the gaitcycle and 43% in the gait cycle and predictively initiate the pull onlyafter lapse of that computer delay.

Further, to get a more accurate assessment of where the person is intheir gait cycle, the controller could also monitor the tension forceover time and look at several points where it crosses different forcethresholds. In general, the pattern of force versus time will changedepending on the person's walking speed. The slope of theforce-versus-time curve can also be used to estimate the person'swalking speed (or gait period). The slope should also be used inpredicting where the person is in the gait cycle since the peak tensionforce is also a function of the person's walking speed, where thetension decreases as walking speed increases. In summary, a controllercan be configured to made that estimates(Current % InGait,GaitPeriod)=f(CableForce(t),CableForce(t−1), . . .,CableForce(t−N))

where f( ) is a function and N is the number of samples used to trackthe cable force over time. N can be as small as 1 (using two samples toestimate the slope) or as large as 100-1000, depending on the samplerate of the force sensor. To get a good estimate of the slope, forcesshould be examined for the period of around 5-10% of the gait period.That is, if our gait period is 1 second, then to estimate the slope, thecontroller should use samples from the current time back to 0.05 or 0.1seconds prior to the current time.

Yet further, instead of having the cable (e.g., Bowden cable 142) orcables (e.g., for a multi-joint activated soft exosuit) pull in (andrelease) with a position profile (% of gait), there are other controloptions. The motor could pull in with some specified velocity until acertain peak force is reached. The motor could also pull such that theforce at the ankle follows some prescribed force trajectory. The motorcould also pull in with some specified velocity until it detects forcedecreasing due to the biomechanics of walking. Similarly to how thetension increases in the soft exosuit and cable at 15-35% in the gaitcycle due to the biomechanics of walking and the soft exosuit changinglength, the tension in the soft exosuit and cable will also decrease ataround 60-65% in the gait cycle due to the configuration of the bodycausing the soft exosuit to slacken. In particular, the ankle lifting upat around 60-65% of the gait cycle and the knee bending cause the softexosuit to become slack even if the cable is held at a fixed length oris being pulled by the motor (and decreasing in length) at moderate orslow rates. This decrease in force due to the biomechanics can be usedas a trigger for when the cable should be released and fed out again. Atthat point, the cable should be released at some specified velocity orfollowing a certain force trajectory back to the nominal tensionedpoint.

In general, the process of tensioning and releasing the cable(s) can bedone following a force trajectory, position trajectory, velocitytrajectory, some combination of these, or some other scheme.

As noted above, real-time measurements of human biological joint anglesusing wearable strain sensors (e.g., hyperelastic strain sensorscomprising liquid metal conductors, conductive fibers integrated withnonconductive stretchable fabric, etc.) or other type(s) of sensors(e.g., inertial systems, angular velocities measured from a plurality ofgyroscopes/accelerometers attached on different limb portions, etc.) canbe used to inform the control system of the soft exosuit and/or ofassistive exoskeletons when performing daily-life or field tasks, suchas represented in FIG. 69. The information provided by these strainsensors (or other sensors providing positional data or derivativesthereof) can be used to classify different human motions such aswalking, going up or down the stairs, incline walking, crouching,crawling, stopping, jumping, etcetera, once suitable baselines areestablished either for the wearer or for a population similar to thewearer (e.g., anatomically similar). Real-time analysis of human motionis of vital importance when a person is wearing a wearable exoskeletonor assistive devices in real-world applications (i.e., out-of-lab). Theassistance required to perform these various activities totally differsand a strategy that works well for walking won't benefit the user or mayeven destabilize the user's motion when the user performs variations ofthe same task (incline walking) or performs other movements. In accordwith at least some aspects of the present concepts, sensors integratedinto the soft exosuit (e.g., strain sensors, pressure sensors,gyroscopic sensors, accelerometers, etc.) are used to measure one ormore joint rotations or limb motions (e.g., rotation of the hip, kneeand/or ankle), or are used to permit determination of one or more jointrotations or limb motions, and this information is compared to referencedata for the wearer of the soft exosuit (e.g., wearer baseline data) orfor a population having similar characteristics (e.g., look-up tables,algorithms, etc.) to determine kinematics and/or other characteristicsof motion. The determined motion(s) can then be used by the soft exosuitcontrol system to affect on-board systems (e.g., actuation times and/ormagnitudes for a single joint type, actuation times and/or magnitudesfor a plurality of joint types, etc.) or to communicate with and/oreffect local or remote external systems (e.g., worn exoskeleton). Thus,the obtained classification of human motion(s) can be used to define astate-machine that updates in real-time to inform the control system asto what motion(s) the wearer is performing.

Further, where a plurality of soft exosuits are deployed amongst aplurality of users (e.g., a squad of soldiers), motion data from theplurality of soft exosuits are communicated, in real-time, to one ormore local or remote external systems and the motion data analyzed(either singly or in combination with other measured data, such asposition data for each wearer, respiration, heartrate, etc.), in theaggregate to determine the motions of the group and characteristics ofsuch motion, infer causes for deviations from expected values, andinitiate corrective actions or engage other local or remote systemsdeemed appropriate responsive to such characteristics of motion. By wayof example, if a squad of soldiers is expected to be walking along aroad, and GPS data for the soldiers shows the soldiers moving toopposing sides of the road, GPS data alone doesn't indicate whether thesoldiers are taking cover in ditches or simply allowing a vehicle topass. However, if the same GPS data is combined with information thatshowed rapid movement of each of the soldiers combined with an assumedprone or semi-prone position, such information transmitted in real-timeto a remote control system could automatically initiate an alert thatthe squad has possibly been engaged by hostiles and data on nearbyassets could automatically be routed to appropriate decision makersremotely or in the field. Thus, the soft exosuit sensor data is not onlyutilizable by a soft exosuit control system for an individual user, butcan be used by external (command and) control systems, which may utilizeas control inputs data from a single channel (e.g., one soft exosuit) ormultiple channels (e.g., a plurality of soft exosuits).

In accord with the aforementioned use of sensor data, such sensor datacan also be used to provide to the soft exosuit control systeminformation about the user's gait, such as gait phase, speed andamplitude. These parameters will allow the force profiles delivered tothe user biological joints during walking by actuator(s) 200 to beadapted in real-time, resulting in an increased efficiency of theassistance. By way of example, such utilization of sensor data canpermit elimination of other sensors, such as the aforementioned footswitch sensors, which would be rendered unnecessary.

FIG. 70 shows an example of one exemplary advanced control architectureadapted to change soft exosuit assistance based on detected soft exosuitwearer motions. Since the assistive forces required by each joint whileperforming different motions are completely different, a control systemshould be configured to provide adequate assistive forces to the userduring the different considered activities. In FIG. 70, a human motionpattern recognition algorithm output, such as was generally describedabove in relation to FIGS. 68-69, informs the control system todetermine the reference trajectory forces to be delivered to the user.Humans adapt the biological impedance of their limbs when performingdifferent motions, such as walking in an inclined terrain, running,etcetera. Implementing a position-based admittance control with force asan input (F_(Ref)) allows defining the virtual impedance (inertia,damping and stiffness) felt by the user during actuation (F_(Suit)),provided that the inner position control loop compensates the dynamicand friction components. The use of on-board soft exosuit sensors thuspermits utilization of sensed motions in combination with an admittancecontrol architecture to adapt the soft exosuit to work with the userbased on the movements of the user, as shown in FIG. 70, providing morenatural and efficient actuation. The human motion pattern recognitionwould be used to change the assistance force of an active exoskeletonand to change the virtual impedance delivered to the user.

FIG. 71A-71H show aspects of an soft exosuit 100 in accord with at leastsome aspects of the present concepts. In relation to the actuator system200 described above in FIGS. 29-43B, the actuator system 200 shown in71A-71H show a number of beneficial improvements thereto (e.g. furtherreduction in weight, increased reliability, etc.). By way of example,the higher stiffness of the four-plate frame 500 makes it possible toreduce wall thicknesses and to cut off more material, which resultsitself in a weight of 1.5 kg. The actuator 200 shown in FIGS. 71A-71Halso comprises a different design for the lower pulleys 510. Where theprior design of the lower pulleys did not absolutely prevent cable jam,the design shown in FIGS. 71A-71H makes cable jams impossible. Flangeradii have increased and an additional part 520, a guide structure, isadded on each side, such as by mounting to the side plates directlybetween the rotating pulleys, with only small tolerances to prevent thewebbing from being lodged between adjacent rotating parts. As anotherenhancement, the load cell design is changed as well to permit use ofhigh quality (e.g., low noise), market-based load cells. Instead of beamload cells, as described above, the design of FIG. 71C uses button loadcells 530. FIGS. 71A-71H also variously show, for reference, the timingpulley 271, pulley wheel 225, and cutouts 402 shown above with respectto FIGS. 29-43B.

FIGS. 71D-71H show images of a soft exosuit 100 having an actuator 200,as described above, configured to provide hip actuation using thighbrace 120 and connection elements 800. As shown, the actuator 200comprises two actuators, each configured to actuate a specific side ofthe body (left/right). In FIG. 71H, the left channel of the actuator 200has been removed.

FIGS. 72-74 show several possible implementations of a soft suit 600comprising a passive systems configured to support hip flexion and/orhip extension. The soft suit 600 and disclosed passive systems can beused in combination with the soft exosuit 100 described herein, or couldbe used entirely separately therefrom as a stand-alone system. Moreover,the soft suit 600 may advantageously integrate sensors such as, but notlimited to, a plurality of hyperelastic strain-sensors (such asdisclosed in WO 2013/044226 A2) to measure changes in angle of monitoredjoints (e.g., hip) or changes in soft suit deformation. This data and/orother sensor data from other sensors, may be output to a local storagedevice (e.g., solid state memory device) and/or wirelessly transmittedto a local device (e.g., via Bluetooth, etc.) or a remote device forstorage and/or processing.

Turning to FIG. 72(a), the passive soft suit 600 is a garment based on aspandex short with added material to make certain paths inextensible inthe garment. In FIG. 72(a), label 1 is inextensible fabric providingforces on the right leg, and label 2 is inextensible fabric providingforces on the left leg. Element 3 is a stretchy spandex material,connected to (e.g., sewn) the inextensible fabrics along their edges orprovided as a base layer underneath all of the other elements. Element4, which is optional, is an elastic region to permit the soft suit 600to fit closely around the waist, while elements 5, which are optional,are elastic regions to permit the soft suit to fit closely around thethighs. Both of optional element 4 and optional elements 5 can comprisespandex or can comprise a different material with a different stiffnessand/or hysteresis than the spandex. If elements 4 and 5 of FIG. 72(a)are not included, the inextensible fabric 1 and 2 should connecttogether in these regions. Elements 4, 5 could alternatively comprisesnaps, hooks, VELCRO®, a zipper, a lacing system based on shoelace orstring, or a tensioning system based on straps, or a variety of otherclosure devices. The important aspect is that these regions permit thesoft suit 600 to attach closely around the waist and leg. Instead of orin addition to elements 4, 5 being located at the back of the thigh andwaist, they could be located at a variety of other locations on the softsuit, for example on the sides of the waist (to replace element 4), inthe front of the abdomen on the angled straps (to replace element 4), inthe front of the thigh where the inextensible fabric makes an “X”, or onthe sides of the thigh (to replace elements 5), among other locations.An additional waist belt 600 is optionally added around the top of thesoft suit 600. This waist belt 600 could also secure in the center withelastic, VELCRO®, lacing, or any of a variety of other conventionalsecurement methods.

Similarly, inextensible fabric elements 1, 2 can comprise a variety ofmaterials, including fabric which is stiffer than spandex but stillstretchy. In this case, elements 4, 5 would not be necessary because theentire soft suit 600 would expand and contract to fit the wearer snugly.The particular paths that elements 1, 2 take can follow any of the pathsthat transmit force, as described previously. For example, elements 1, 2should ideally extend over the top of the iliac crest of the pelvis onthe opposite side of the body, while on the same side of the body theycan wrap around the body below the iliac crest, or could have one branchgo below the iliac crest and one branch go above the iliac crest. Thissoft suit 600 functions by pulling forward on the thigh when it isextended backwards, thereby creating a torque around the hip which canaid the return of the leg to the neutral position, which is influencedby soft suit 600 position when the soft suit is donned or movement ofthe soft suit subsequent thereto.

FIG. 72(b) shows the soft suit 600 in FIG. 72(a) with an additionalelement 6 positioned over the crease between the wearer's thigh andabdomen. This element 6 can comprise an elastic material to provide agiven stiffness in conjunction with elements 1, 2, which would belargely inextensible in this case. Adding the elastic element 6 woulddecrease the stiffness of the soft suit 600, and thereby provide asmaller torque around the hip for a given angular displacement of thehip. However, adding an elastic element (which could comprise rubber,silicone, a different type of spandex, several layers of spandex,elastic strapping, or other materials) could reduce the hysteresis ofthe overall system, thereby returning more energy to the wearer's leg ifthe leg is deflected in flexion and then moves forward again.

FIG. 73(a) shows a soft suit 600 similar to that in 72(b), except thatthe configuration depicted in FIG. 73(a) is designed to assist with hipextension. In this case, if the wearer moves their knee forward, thesoft suit 600 will pull on the front of the thigh to try to return thethigh to a vertical orientation. This could be useful in severalinstances, such as when walking downhill, where the hip takes anincreased amount of torque. The soft suit 600 could, in this case,provide some of that force so the muscles do less work. Another possibleuse for the soft suit 600 would be if someone was walking uphill whilecarrying a heavy backpack. In this case, there is a large moment aboutthe hip at the beginning of the gait cycle as the person lifts theirentire body mass and backpack mass up with one leg. If the user werewearing the soft suit 600 adapted to assist with hip extension, theywould still have to expend additional energy lifting the leg beforeplanting it on the ground, but this additional energy would go intostretching the suit (for example, stretching element 6 which is at thecrease of the posterior and thigh). Once the wearer had planted theirfoot on the ground, the soft suit 600 could then apply a force inparallel with their gluteus muscles, permitting them to do less workduring the part of the gait when they lift up their mass and theirbackpack's mass. Finally, FIG. 73(b) shows a soft suit 600 systemadapted to assist with both hip flexion and hip extension, by combiningthe systems of FIGS. 72(a) and 73(a).

FIG. 74 shows another possible implementation where the soft suit 600 ofFIGS. 72-73 comprises an elastic element 6 at the front of the thigh andfurther depicts a method of adjusting the length of the suit in thefront of the thigh. In this case, the wearer could tighten or loosen thesoft suit 600 (e.g., by securing Velcro® at the top edge of element 6higher or lower on the front of the soft suit) to fit their preference.In this case, element 6 would be separated from the underlying spandexso it could move up or down to be secured higher or lower on the frontof the soft suit 600. The inextensible fabric at the top edge of element6 would have the complementary means of securing down element 6. Forexample, element 6 could have hook Velcro® facing downward on the topedge. The inextensible fabric underneath could have loop Velcro® facingupward some distance above and below the nominal position of element 6.Elements 4 and 5 in FIGS. 72 and 73 could also have this construction.

As to the soft exosuit 600 embodiment shown in FIG. 72A, during normalwalking, around 30-70% of the gait cycle, the hip extends. Initially,the hip absorbs power from 30-50% in the gait cycle, and then generatespower from 50-70%. When wearing the FIG. 72A-72B embodiment of the softexosuit 600, the soft exosuit will take over some of the function of themuscles in absorbing and generating power during this time period. Theembodiment of the soft exosuit 600 in FIG. 73A, may be particularlybeneficial in movement over diverse terrain (e.g., rugged territory,mountain climbing, etc.), either going uphill or downhill. During bothuphill and downhill walking, the hip supports an increased torque in theextension direction. For downhill walking, the soft exosuit 600 in FIG.73A will passively provide support to the hip to reduce the muscularactivity required. For uphill walking, the soft exosuit 600 in FIG. 73Amust be pre-stretched by lifting the knee when the foot is being placedon the ground. Then, the suit will act in parallel with the muscles toreduce the extension torques required by the body.

Although primary functional elements of the soft exosuit 600 in FIGS.72-73 are shown, additional elements may be included. For example,functional fabric (e.g., inextensible fabric, stretchable fabric, etc.)may also be incorporated in regions other than shown, such as extendingto the sides of the leg.

Turning again to the aforementioned embodiments of the soft exosuit 100,such embodiments can be advantageously used for a variety of differentapplications including, but not limited to medical applications,sporting or recreational applications, and/or control system inputs. Asto medical applications, the soft suit 100 provides a cost-effective,easy to use (e.g., easy to don and doff), comfortable sensing suit topermit improved evaluation of patient outcome (e.g., range of motion)both during and after a rehabilitation therapy (e.g., post-strokerehabilitation, physical rehabilitation, etc.) and may be used in theclinic, and/or at a patient's home. The sensed data (e.g., joint angles,performance of recommended repetitions of physical therapy, etc.) may beused not only to track progress to use as inputs for changes to atherapy regimen, but may also be used (or may be required to be used) toensure compliance, such an by a health insurance company seeking toensure that the patient is doing their part to ensure their ownwell-being.

In accord with least some aspects of the soft suit 100, the sensed datamay be advantageously saved locally to a physical memory device (e.g.,solid state memory) that can then be inserted into a user's homecomputer, wireless device, or home health care monitoring device (e.g.,datalogger and/or wireless communication device) for recordation and/ortransmission. In some aspects, the soft suit 100 sensors areadvantageously networked (e.g., via Bluetooth or other frequency-hoppingspread spectrum (FHSS) system) with a user's device, such as a smartwatch, smart phone, or heads-up display device.

Returning to the soft exosuit 100, and particularly to a system built toassist hip extension both during normal and walking uphill/downhill(see, e.g., soft exosuit of FIGS. 71A-71H), FIG. 75 shows hip jointtorque during level walking where the soft exosuit is actuating betweenabout 0% to about 25% of the gait cycle, not actuating between about 25%to about 75% of the gait cycle, and again actuating between about 75% toabout 100% of the gait cycle. The positive torque corresponds to hipextension (portion of curve associated with actuation) whereas thenegative torque corresponds to hip flexion (portion of curve associatedwith no actuation). Two control schemes are useful in providing suchassistance, position-based control and force based and admittancecontrol.

As to position-based control, during normal gait, hip extension startsbefore heel strike occurs. A position-based control scheme needs to takesuch characteristic into consideration. In order to get informationabout the step frequency during normal gait, foot switches are used todetect the heel strikes. The time for one step is measured bysubtracting the time for the last heel strike from the time of theprevious one. This information is then stored in a buffer whichconsequently comprises the step frequency. By averaging the step datasaved in the buffer, or data derived therefrom, the next heel strike canbe predicted by adding that specific time to the last heel strike event.In that context, position control means that a fixed trajectory isreplayed if the system time reaches the predicted time for the next heelstrike. In order to adapt the position controller to different speeds,the fixed trajectory is time scaled, meaning that the peak of thetrajectory never changes but the time the motor reaches that maximum canchange depending on the measured step frequency.

FIG. 76 shows an extract of recorded data during ground level walkingdepicting curves for force profile, motor position and footswitchsignal. It can be seen from curve 705 that the motor starts spinningbefore heel strike occurs, shown by curve 710. By playing back thescaled motor trajectory, a corresponding force is generated, as shown bycurve 715. It is to be noted that the force is the force in the cableand not the actual hip moment. The main disadvantage of suchposition-based control is that the system needs to be at least slightlypretensioned to permit the trajectory to be played back to apply thedesired forces. Otherwise, the system would mainly wind up slack cable,resulting in low applied forces.

As to force based and admittance control, force based control canadvantageously be used to track hip motion. By always having a slight(<5N) tension in the cable, the controller is able to follow the hipmotion, which eliminates the main disadvantage of the position basedcontroller. Since the position based control showed good results for theapplied moment and for assisting the user, admittance control is chosenas an advanced controller for the system. The motor is still positioncontrolled, which shapes the inner control loop. By developing anefficient position controller, the physical system properties likeinertia and friction can be neglected. By adding an outer admittancecontrol loop, the system behavior can be simulated and shaped to thephysical system accordingly. The controller set point, the desiredvalue, and the error are now forces in that specific case.

In order to follow the correct torque profile for hip extension (seeFIG. 75), foot switches are used to synchronize the controller in thefirst place. The exact same principle is used as for the positioncontroller. Tracking the hip motion by using the admittance controllerenables the system to work without foot switches as well. Foot switchescan only provide the time a heel strike occurs. Similar information canbe obtained by reading the motor encoder and marking the point whereextension changes into flexion. By knowing that specific point, the sameprinciple can be applied as for using footswitches. As mentioned, themotor encoder signal is used to estimate the hip angle. Although, it isnot necessary to know the exact angle since the only information neededto synchronize the controller with gait is the change between extensionand flexion.

Although the above concepts regarding the soft exosuit 100 and the softsuit 600 have been generally described in terms of land-basedapplications adapted generally for activities such as walking, running,or rehabilitation, both the soft exosuit and the soft suit are adaptablefor utilization in wet or potentially wet environments (e.g.,cross-country skiing, scuba diving, etc.) using suitable materials,enclosures, and connections appropriate to the activity. By way ofexample, the soft exosuit 100 and the soft suit 600 could be integratedinto a wet suit, or a dry suit, with the actuation system 200 enclosedin a neutral buoyancy dry bag that the diver can attach to the airtank(s).

In applications where it is desirable for the soft exosuit 100 or thesoft suit 600 to wirelessly communicate with a remote computer or remotecontrol system (and/or command and control system), a wearable antennamay be advantageously integrated into the soft exosuit 100 the soft suit600, such as, but not limited to the Pharad (Hanover, Md.) wearableantenna products (frequency and application selected, as appropriate,for the activity) or Patric (Helsinki, Finland) washable-wearableantenna.

Other embodiments are within the scope and spirit of the invention. Forexample, due to the nature of software, functions described above can beimplemented using software, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

In accord with at least some aspects of the present concepts, the softexosuit disclosed herein is, advantageously, sufficiently flexible andlight-weight to permit the soft exosuit to be worn under clothing. In atleast some aspects, the soft exosuit connection elements, nodes andoptionally anchor elements are integrated into a wearable undergarment.

Still further, the soft exosuit 100 in accord with any of the disclosedaspects of the present concepts may be further configured with tointeract wirelessly with a variety of other user devices and/orinteracting through wired connections with a variety of other userdevices. By way of example, the soft exosuit 100 may comprise ports andconnectors adapted to enable utilization of the power supply from thesoft exosuit to power one or more other external devices (e.g., acommunication device, night vision goggles, GPS equipment, etc.) as theneed may arise (e.g., operation in a Tier-1 environment), should therebe sufficient power in the soft exosuit to spare. Similarly, ports andconnectors may be provided to enable recharging of the soft exosuitbattery system from an external source (e.g., vehicle battery,stationary battery, portable solar cells, wearable solar cells, AC poweroutlet in combination with an adapter suitable for the power gridvoltage/frequency, etc.).

FIG. 79 shows an example of a soft exosuit component (here a footwearattachment element) made of a soft material (e.g., neoprene) comprisinga haptic actuator (e.g., piezoelectric actuators, Piezo Fibers, BimorphPiezo, Non-Rigid Piezo, Electroactive Polymers, etc.) to provide inputsto the wearer according to at least some aspects of the presentconcepts. It at least one aspect, small haptic actuators areadvantageously integrated into one or more areas of the soft exosuit 100(e.g., anywhere covered by fabric in FIG. 54A, under connectingelements, under thigh brace 120, etc.). These haptic actuators could besub-threshold (so person doesn't feel vibration) for a stochasticresonance (SR) effect or supra-threshold (so person does feel vibration)and provide a user-machine interface capable of informing the user as towhether the wearer is doing something correctly or incorrectly (e.g.,performing a movement correctly, performing a movement incorrectly,approaching a preset limit, exceeding a preset limit, performing aminimum required motion of a joint, etc.). In the example of FIG. 79,piezoelectric actuators having an insulated coating are embedded withina fabric pocket on an inside of an ankle brace. An insulated cableconnects an enclosed electronics box to the piezoelectric actuators.

Such haptic actuators can acts as a feedback control system for humanbalance. In this feedback loop, an external stimulus triggers receptorsin the body, mechanoreceptors, to send information about the stimulus tothe central nervous system, which then signals the muscles. Themechanoreceptors for balance are found in the skin, muscle, tendon, andother soft tissues of the lower limbs. For the sensory neurons to send asignal, the stimulus must exceed the minimum sensory threshold, whichcan increase with fatigue or injury. The presence of a particularsub-threshold level of noise effectively lowers this sensory thresholdand can be used to enhance signal recognition and detection (SR). Thus,haptic devices, whether sub-threshold or supra-threshold may enhanceperformance of static and dynamic balance activities for the wearer ofthe soft exosuit 100.

In at least some aspects of the present concepts, one or more of thesoft exosuit components may comprise an interior lining (and/oroptionally exterior lining) comprising a reversible adhesive (e.g. a“gecko style” adhesive comprising nanoscale surface features such as,but not limited to, nano polymer pillar arrays). Such a reversibleadhesive can facilitate retention of the soft exosuit is a fixedlocation relative to the body. Alternatively, other surface treatmentsmay be selectively applied to enhance surface properties of the interioror exterior of the soft exosuit.

FIGS. 80A-8B show an example of soft exosuit components according to atleast some aspects of the present concepts. The soft exosuit 100 shownis configured to provide an extension torque around the knee, as well asplantar flexion torque around the ankle and extension torque to the hip.During squatting or downhill walking, the ankle, knee, and hip havethese torques from 15-40% or 15-60% of the gait cycle depending on thesteepness of the slope and the person's gait. In FIG. 80(a), the softexosuit 100 is shown to include a waist belt 1 comprising a flap thatextends over the gluteal region to the top of the thigh and fabricregions 2, 3 over the front of the thigh and front of the shin,respectively. The soft exosuit 100 is also shown to include an element 4surrounding the foot as an attachment, which has the same functionalityas element 130 in FIGS. 26A-26F, except it contacts more of the footarea to distribute the forces more uniformly. Fabric regions 2, 3 arebordered by a stretch of Bowden cable sheath on their sides, drawn asthick lines and labeled as elements 5, 6 for the outside of the leg(lateral aspects). The inside of the leg (medial aspects) has similarsheaths on the edges of elements 2, 3, although those are not shown inFIGS. 80A-8B.

A cable 7 connects the waist belt 1 and foot attachment 4, passingthrough these cable sheaths 5, 6 on the inside and outside of the legs.A second cable (not shown) passes from the waist belt 1 to the heel onthe inside of the leg. The positioning of the cable 7 ends and thesheaths 5, 6 at the edges of fabric regions 2, 3 cause the cable toextend at the back of the hip joint, in front of the knee joint (labeled8 in FIG. 80A), and behind the ankle joint. As such, if there is tensionin the cable 7, then the appropriate torques are created about thesejoints. The cable 7 could comprise a spring or other resilient orstretchy material to permit additional energy storage or absorption. InFIG. 80(a), the system shown is a passive system in which the cable 7can be tensioned (e.g. manually, etc.) to an appropriate level beforedownhill walking is begun. The cable 7 can then be loosened for uphillor level walking or other activities.

FIG. 80(b) shows the same suit as in FIG. 80(a) except with the additionof another segment of Bowden cable sheath 9 and an actuator, clutch, ordamper unit 10. An actuator could create tension in the cable 7 at theappropriate points in the gait cycle (e.g. between about 15-40% for awalking gait cycle) so as to increase the moment that the soft exosuitcreates around these joints, or just increase the tension to a baselevel once it is detected that the wearer is walking downhill (e.g.,through one or more sensors providing data to controller indicative ofwalking downhill including but not limited to accelerometer data, GPSdata, heel strike force, etc.). Alternatively, a clutch unit (e.g., 10)could reel in the cable 7 (e.g., with a low force over a portion of, ormost of, the gait cycle) and hold the cable in place to create forces inthe suit during appropriate points in the gait cycle. In other aspects,such a clutch unit (e.g., 10) could be configured to continuously reelin the cable with a light spring and then, if the cable 7 is pulled outdue to the biomechanics of walking, the clutch unit would apply adamping force to the cable, causing a transient force in the suit whichcould benefit the user.

Further, while the description above refers to the invention, thedescription may include more than one invention. Each of theseembodiments and obvious variations thereof is contemplated as fallingwithin the spirit and scope of the claimed invention, at least someaspects of which are set forth in the following claims.

What is claimed is:
 1. A wearable soft exosuit comprising: a firstanchor element configured for positioning at or near a first body partof a person wearing the wearable soft exosuit; a second anchor elementconfigured for positioning at or near a second body part of the personwearing the wearable soft exosuit; an actuation member coupled to thesecond anchor element configured to be behind an ankle joint of theperson; a plurality of connection elements extending between andconnected directly or indirectly to the first anchor element and theactuation member, and at least one of the plurality of connectionelements spanning at least one joint disposed between the first anchorelement and the second anchor element; at least one actuator; and atleast one controller configured to actuate the at least one actuator ata predetermined time during movement of the at least one joint togenerate a beneficial moment about the at least one joint, wherein eachof the plurality of connection elements comprise webbing, a strap, acord, a functional textile, fabric, a wire, a cable, or a compositematerial, wherein the at least one actuator comprises at least one motordriven actuator, at least one pneumatic actuator, or at least onehydraulic actuator, wherein the second anchor element comprises afootwear anchor element, wherein the first anchor element comprises awaist belt anchor element, wherein the at least one actuator isconfigured to apply a tensile force to the second anchor element via theactuation member, wherein the plurality of connection elements comprisea first connection element on a first side of the waist belt anchorelement configured to extend from the waist belt to a position adjacenta center of the wearer's first thigh, a second connection element on thefirst side of the waist belt anchor element configured to extend fromthe waist belt to a position adjacent a center of the wearer's secondthigh, a third connection element on a second side of the waist beltanchor element configured to extend from the waist belt to a positionadjacent a center of the wearer's second thigh, and a fourth connectionelement on the second side of the waist belt anchor element configuredto extend from the waist belt to a position adjacent a center of thewearer's first thigh, wherein the first connection element and thefourth connection element are connected to form a first node at theposition adjacent the center of the wearer's first thigh, and whereinthe second connection element and the third connection element areconnected to form a second node at the position adjacent the center ofthe wearer's second thigh.
 2. The wearable soft exosuit according toclaim 1, further comprising: a first thigh brace for the wearer's firstthigh; a second thigh brace for the wearer's second thigh; one or moreconnection elements connecting the first node to the first thigh brace;and one or more connection elements connecting the second node to thesecond thigh brace.
 3. The wearable soft exosuit according to claim 2,further comprising: a first lateral calf connection element connected tothe first thigh brace; a first medial calf connection element connectedto the first thigh brace; a second lateral calf connection elementconnected to the second thigh brace; and a second medial calf connectionelement connected to the second thigh brace.
 4. The wearable softexosuit according to claim 3, wherein the at least one actuatorcomprises a motor driven actuator configured to drive a first cableattached to a first footwear anchor element on a wearer's first foot andto drive a second cable attached to a second footwear anchor element ona wearer's second foot.
 5. The wearable soft exosuit according to claim4, wherein the first footwear anchor element and the second footwearanchor element comprise a footwear insole insert defining a cablechannel, wherein a distal end of the first cable is fixed to the firstfootwear anchor element at a position proximal to the ankle joint tocreate a torque around the first ankle when the first cable is actuated,and wherein a distal end of the second cable is fixed to the secondfootwear anchor element at a position proximal to the ankle joint tocreate a torque around the second ankle the second cable is actuated. 6.The wearable soft exosuit according to claim 1, wherein the actuationmember includes a flexible ribbon or a flexible cable.
 7. The wearablesoft exosuit according to claim 1, wherein the plurality of connectionelements are non-extensible.
 8. The wearable soft exosuit according toclaim 1, wherein the plurality of connection elements aresemi-extensible.
 9. The wearable soft exosuit according to claim 1,wherein the beneficial moment assists or promotes normal plantarflexionmotion of the ankle joint.
 10. The wearable soft exosuit according toclaim 1, wherein the beneficial moment assists or promotes normalflexion motion of a hip joint of the person.
 11. The wearable softexosuit according to claim 1, wherein the beneficial moments assist orpromote normal plantarflexion motion of the ankle joint and normalflexion motion of a hip joint.
 12. A wearable soft exosuit comprising: afirst anchor element configured for positioning at or near a first bodypart of a person wearing the wearable soft exosuit; a second anchorelement configured for positioning at or near a second body part of theperson wearing the wearable soft exosuit; an actuation member coupled tothe second anchor element configured to be behind an ankle joint of theperson; a plurality of connection elements extending between andconnected directly or indirectly to the first anchor element and theactuation member, and at least one of the plurality of connectionelements spanning at least one joint disposed between the first anchorelement and the second anchor element; at least one actuator; and atleast one controller configured to actuate the at least one actuator ata predetermined time during movement of the at least one joint togenerate a beneficial moment about the at least one joint, wherein atleast some of the plurality of connection elements are connected to format least one node, wherein each of the plurality of connection elementscomprise webbing, a strap, a cord, a functional textile, fabric, a wire,a cable, or a composite material, wherein the at least one actuatorcomprises at least one motor driven actuator, at least one pneumaticactuator, or at least one hydraulic actuator, wherein the second anchorelement comprises a footwear anchor element, wherein the first anchorelement comprises a waist belt anchor element, wherein the at least oneactuator is configured to apply a tensile force to the second anchorelement via the actuation member, wherein the plurality of connectionelements comprise a first connection element on a first side of thewaist belt anchor element configured to extend from the waist belt to aposition adjacent a center of the wearer's first thigh, a secondconnection element on the first side of the waist belt anchor elementconfigured to extend from the waist belt to a position adjacent a centerof the wearer's second thigh, a third connection element on a secondside of the waist belt anchor element configured to extend from thewaist belt to a position adjacent a center of the wearer's second thigh,and a fourth connection element on the second side of the waist beltanchor element configured to extend from the waist belt to a positionadjacent a center of the wearer's first thigh, wherein the firstconnection element and the fourth connection element are connected toform a first node at the position adjacent the center of the wearer'sfirst thigh, and wherein the second connection element and the thirdconnection element are connected to form a second node at the positionadjacent the center of the wearer's second thigh.
 13. The wearable softexosuit according to claim 12, further comprising: a first thigh bracefor the wearer's first thigh; a second thigh brace for the wearer'ssecond thigh; one or more connection elements connecting the first nodeto the first thigh brace; and one or more connection elements connectingthe second node to the second thigh brace.
 14. The wearable soft exosuitaccording to claim 13, further comprising: a first lateral calfconnection element connected to the first thigh brace; a first medialcalf connection element connected to the first thigh brace; a secondlateral calf connection element connected to the second thigh brace; anda second medial calf connection element connected to the second thighbrace.
 15. The wearable soft exosuit according to claim 14, wherein theat least one actuator comprises a motor driven actuator configured todrive a first cable attached to a first footwear anchor element on awearer's first foot and to drive a second cable attached to a secondfootwear anchor element on a wearer's second foot.
 16. The wearable softexosuit according to claim 15, wherein the first footwear anchor elementand the second footwear anchor element comprise a footwear insole insertdefining a cable channel, wherein a distal end of the first cable isfixed to the first footwear anchor element at a position proximal to theankle joint to create a torque around the first ankle when the firstcable is actuated, and wherein a distal end of the second cable is fixedto the second footwear anchor element at a position proximal to theankle joint to create a torque around the second ankle the second cableis actuated.
 17. The wearable soft exosuit according to claim 12,wherein the actuation member includes a flexible ribbon or a flexiblecable.
 18. The wearable soft exosuit according to claim 12, wherein theplurality of connection elements are non-extensible.
 19. The wearablesoft exosuit according to claim 12, wherein the plurality of connectionelements are semi-extensible.
 20. The wearable soft exosuit according toclaim 12, wherein the beneficial moment assists or promotes normalplantarflexion motion of the ankle joint.
 21. The wearable soft exosuitaccording to claim 12, wherein the beneficial moment assists or promotesnormal flexion motion of a hip joint of the person.
 22. The wearablesoft exosuit according to claim 12, wherein the beneficial momentsassist or promote normal plantarflexion motion of the ankle joint andnormal flexion motion of a hip joint.
 23. A wearable soft exosuitcomprising: a first anchor element configured for positioning at or neara first body part of a person wearing the wearable soft exosuit; asecond anchor element configured for positioning at or near a secondbody part of the person wearing the wearable soft exosuit; an actuationmember coupled to the second anchor element configured to be behind anankle joint of the person; a plurality of connection elements extendingbetween and connected directly or indirectly to the first anchor elementand the actuation member, and at least one of the plurality ofconnection elements spanning at least one joint disposed between thefirst anchor element and the second anchor element; at least oneactuator; and at least one controller configured to actuate the at leastone actuator at a predetermined time during movement of the at least onejoint to generate a beneficial moment about the at least one joint,wherein at least some of the plurality of connection elements areconnected to form at least one node, wherein each of the first anchorelements and second anchor element comprise at least one footwear anchorelement, waist belt anchor element, shoulder strap anchor element, ornode, wherein each of the plurality of connection elements comprisewebbing, a strap, a cord, a functional textile, fabric, a wire, a cable,or a composite material, wherein the at least one actuator comprises atleast one motor driven actuator, at least one pneumatic actuator, or atleast one hydraulic actuator, wherein the second anchor elementcomprises a footwear anchor element, wherein the first anchor elementcomprises a waist belt anchor element, wherein the at least one actuatoris configured to apply a tensile force to the second anchor element viathe actuation member, wherein the plurality of connection elementscomprise a first connection element on a first side of the waist beltanchor element configured to extend from the waist belt to a positionadjacent a center of the wearer's first thigh, a second connectionelement on the first side of the waist belt anchor element configured toextend from the waist belt to a position adjacent a center of thewearer's second thigh, a third connection element on a second side ofthe waist belt anchor element configured to extend from the waist beltto a position adjacent a center of the wearer's second thigh, and afourth connection element on the second side of the waist belt anchorelement configured to extend from the waist belt to a position adjacenta center of the wearer's first thigh, wherein the first connectionelement and the fourth connection element are connected to form a firstnode at the position adjacent the center of the wearer's first thigh,and wherein the second connection element and the third connectionelement are connected to form a second node at the position adjacent thecenter of the wearer's second thigh.
 24. The wearable soft exosuitaccording to claim 23, further comprising: a first thigh brace for thewearer's first thigh; a second thigh brace for the wearer's secondthigh; one or more connection elements connecting the first node to thefirst thigh brace; and one or more connection elements connecting thesecond node to the second thigh brace.
 25. The wearable soft exosuitaccording to claim 24, further comprising: a first lateral calfconnection element connected to the first thigh brace; a first medialcalf connection element connected to the first thigh brace; a secondlateral calf connection element connected to the second thigh brace; anda second medial calf connection element connected to the second thighbrace.
 26. The wearable soft exosuit according to claim 25, wherein theat least one actuator comprises a motor driven actuator configured todrive a first cable attached to a first footwear anchor element on awearer's first foot and to drive a second cable attached to a secondfootwear anchor element on a wearer's second foot.
 27. The wearable softexosuit according to claim 26, wherein the first footwear anchor elementand the second footwear anchor element comprise a footwear insole insertdefining a cable channel, wherein a distal end of the first cable isfixed to the first footwear anchor element at a position proximal to theankle joint to create a torque around the first ankle when the firstcable is actuated, and wherein a distal end of the second cable is fixedto the second footwear anchor element at a position proximal to theankle joint to create a torque around the second ankle the second cableis actuated.
 28. The wearable soft exosuit according to claim 23,wherein the actuation member includes a flexible ribbon or a flexiblecable.
 29. The wearable soft exosuit according to claim 23, wherein theplurality of connection elements are non-extensible.
 30. The wearablesoft exosuit according to claim 23, wherein the plurality of connectionelements are semi-extensible.
 31. The wearable soft exosuit according toclaim 23, wherein the beneficial moment assists or promotes normalplantarflexion motion of the ankle joint.
 32. The wearable soft exosuitaccording to claim 23, wherein the beneficial moment assists or promotesnormal flexion motion of a hip joint of the person.
 33. The wearablesoft exosuit according to claim 23, wherein the beneficial momentsassist or promote normal plantarflexion motion of the ankle joint andnormal flexion motion of a hip joint.
 34. A wearable soft exosuitcomprising: a first anchor element configured for positioning at or neara first body part of a person wearing the wearable soft exosuit; asecond anchor element configured for positioning at or near a secondbody part of the person wearing the wearable soft exosuit; an actuationmember coupled to the second anchor element configured to be behind anankle joint of the person; a plurality of connection elements extendingbetween and connected directly or indirectly to the first anchor elementand the actuation member, and at least one of the plurality ofconnection elements spanning at least one joint disposed between thefirst anchor element and the second anchor element; at least oneactuator; and at least one controller configured to actuate the at leastone actuator at a predetermined time during movement of the at least onejoint to generate a beneficial moment about the at least one joint,wherein at least some of the plurality of connection elements areconnected to form at least one node, wherein each of the first anchorelements and second anchor element are formed from at least one ofwebbing, a strap, a cord, a functional textile, fabric, a wire, a cable,or a composite material, wherein each of the plurality of connectionelements comprise webbing, a strap, a cord, a functional textile,fabric, a wire, a cable, or a composite material, wherein the at leastone actuator comprises at least one motor driven actuator, at least onepneumatic actuator, or at least one hydraulic actuator, wherein thesecond anchor element comprises a footwear anchor element, wherein thefirst anchor element comprises a waist belt anchor element, wherein theat least one actuator is configured to apply a tensile force to thesecond anchor element via the actuation member, wherein the plurality ofconnection elements comprise a first connection element on a first sideof the waist belt anchor element configured to extend from the waistbelt to a position adjacent a center of the wearer's first thigh, asecond connection element on the first side of the waist belt anchorelement configured to extend from the waist belt to a position adjacenta center of the wearer's second thigh, a third connection element on asecond side of the waist belt anchor element configured to extend fromthe waist belt to a position adjacent a center of the wearer's secondthigh, and a fourth connection element on the second side of the waistbelt anchor element configured to extend from the waist belt to aposition adjacent a center of the wearer's first thigh, wherein thefirst connection element and the fourth connection element are connectedto form a first node at the position adjacent the center of the wearer'sfirst thigh, and wherein the second connection element and the thirdconnection element are connected to form a second node at the positionadjacent the center of the wearer's second thigh.
 35. The wearable softexosuit according to claim 34, further comprising: a first thigh bracefor the wearer's first thigh; a second thigh brace for the wearer'ssecond thigh; one or more connection elements connecting the first nodeto the first thigh brace; and one or more connection elements connectingthe second node to the second thigh brace.
 36. The wearable soft exosuitaccording to claim 35, further comprising: a first lateral calfconnection element connected to the first thigh brace; a first medialcalf connection element connected to the first thigh brace; a secondlateral calf connection element connected to the second thigh brace; anda second medial calf connection element connected to the second thighbrace.
 37. The wearable soft exosuit according to claim 36, wherein theat least one actuator comprises a motor driven actuator configured todrive a first cable attached to a first footwear anchor element on awearer's first foot and to drive a second cable attached to a secondfootwear anchor element on a wearer's second foot.
 38. The wearable softexosuit according to claim 37, wherein the first footwear anchor elementand the second footwear anchor element comprise a footwear insole insertdefining a cable channel, wherein a distal end of the first cable isfixed to the first footwear anchor element at a position proximal to theankle joint to create a torque around the first ankle when the firstcable is actuated, and wherein a distal end of the second cable is fixedto the second footwear anchor element at a position proximal to theankle joint to create a torque around the second ankle the second cableis actuated.
 39. The wearable soft exosuit according to claim 34,wherein the actuation member includes a flexible ribbon or a flexiblecable.
 40. The wearable soft exosuit according to claim 34, wherein theplurality of connection elements are non-extensible.
 41. The wearablesoft exosuit according to claim 34, wherein the plurality of connectionelements are semi-extensible.
 42. The wearable soft exosuit according toclaim 34, wherein the beneficial moment assists or promotes normalplantarflexion motion of the ankle joint.
 43. The wearable soft exosuitaccording to claim 34, wherein the beneficial moment assists or promotesnormal flexion motion of a hip joint of the person.
 44. The wearablesoft exosuit according to claim 34, wherein the beneficial momentsassist or promote normal plantarflexion motion of the ankle joint andnormal flexion motion of a hip joint.